Replace American English spelling with UK English across tutorial content

matthewwilson · claude · matthewwilson · commit 02fc985841f4 · 2026-02-23T18:42:43.000Z
Standardise spelling in all lesson files, copilot-instructions.md, and
validator scripts: analyze→analyse, specialized→specialised,
summarize→summarise, organize→organise, customize→customise,
optimize→optimise, behaviors→behaviours, visualization→visualisation,
initialized→initialised, synthesized→synthesised.

Code blocks, commands, CSS properties, and technical terms left unchanged.

Co-Authored-By: Claude Opus 4.6 &lt;noreply@anthropic.com&gt;
diff --git a/.github/copilot-instructions.md b/.github/copilot-instructions.md
@@ -95,7 +95,7 @@ The tutorial includes an optional QA track for QA engineers. It is controlled by
 
 ### QA Lessons
 
-- **20: Test Planning from Requirements** — Analyze a feature request and create a structured test plan
+- **20: Test Planning from Requirements** — Analyse a feature request and create a structured test plan
 - **21: Test Case Design & Coverage** — Identify coverage gaps and design test cases using QA techniques
 - **22: Automated Test Generation** — Turn test cases into running Vitest tests
 - **23: E2E Testing with Playwright** — Write Playwright tests for the web UI
diff --git a/tutorial/lessons/00-welcome.md b/tutorial/lessons/00-welcome.md
@@ -29,7 +29,7 @@ You can also use `/agent` and select from the list of tutorial agents.
 11. **Agent Delegation** — Push work to coding agents and built-in specialists
 12. **Hooks in Action** — The automation that powers this tutorial itself
 13. **Git Workflow** — Commits, PRs, and code review with Copilot
-14. **Session Management** — Resume, compress, and organize your work
+14. **Session Management** — Resume, compress, and organise your work
 15. **Programmatic Mode** — Run Copilot from scripts and CI/CD
 16. **Model Selection** — Choose the right model for each task
 17. **CLI Tools & MCP Servers** — Use any CLI tool and structured tool access
diff --git a/tutorial/lessons/03-context.md b/tutorial/lessons/03-context.md
@@ -44,9 +44,9 @@ Use `/clear` (or `/new`) to reset the conversation between unrelated tasks. If y
 
 **This is the single most impactful habit you can build.** Most sessions should be short and focused.
 
-### `/compact` — summarize without losing everything
+### `/compact` — summarise without losing everything
 
-If you're mid-task but your context is getting long, `/compact` tells Copilot to summarize the conversation so far and continue with a compressed context. You can add focus instructions:
+If you're mid-task but your context is getting long, `/compact` tells Copilot to summarise the conversation so far and continue with a compressed context. You can add focus instructions:
 
 ```
 /compact Focus on the API changes
diff --git a/tutorial/lessons/07-planning-mode.md b/tutorial/lessons/07-planning-mode.md
@@ -16,7 +16,7 @@ Planning mode is Copilot's way of avoiding that:
 4. **Present** that plan to you for review
 5. **Only then** proceed — and only if you approve
 
-In Plan Mode, Copilot uses read-only operations to analyze your codebase and asks clarifying questions to understand your requirements before proposing any changes.
+In Plan Mode, Copilot uses read-only operations to analyse your codebase and asks clarifying questions to understand your requirements before proposing any changes.
 
 ### When to use Plan Mode
 
diff --git a/tutorial/lessons/09-custom-agents.md b/tutorial/lessons/09-custom-agents.md
@@ -8,7 +8,7 @@ How to create your own custom agents in Copilot CLI. You've been using them thro
 
 ### What are custom agents?
 
-Custom agents are specialized versions of Copilot that you can tailor to specific workflows, coding conventions, and use cases. When you invoke an agent, Copilot reads the corresponding `.agent.md` file and follows its instructions. Think of them as tailored teammates that follow your standards, use the right tools, and implement team-specific practices.
+Custom agents are specialised versions of Copilot that you can tailor to specific workflows, coding conventions, and use cases. When you invoke an agent, Copilot reads the corresponding `.agent.md` file and follows its instructions. Think of them as tailored teammates that follow your standards, use the right tools, and implement team-specific practices.
 
 ### Where do agents live?
 
diff --git a/tutorial/lessons/10-agent-skills.md b/tutorial/lessons/10-agent-skills.md
@@ -2,7 +2,7 @@
 
 ## What You'll Learn
 
-How to create and use **skills** — reusable knowledge packages that give Copilot on-demand capabilities via `SKILL.md` files. Skills are the counterpart to agents: where agents are specialized personas, skills are focused instruction sets that any agent can invoke.
+How to create and use **skills** — reusable knowledge packages that give Copilot on-demand capabilities via `SKILL.md` files. Skills are the counterpart to agents: where agents are specialised personas, skills are focused instruction sets that any agent can invoke.
 
 ## Concepts
 
@@ -18,7 +18,7 @@ When you invoke a skill, Copilot reads the `SKILL.md` instructions and follows t
 |---------|-------------------|--------|--------|
 | File | `copilot-instructions.md` | `SKILL.md` in a named folder | `.agent.md` |
 | When loaded | Every session, always on | On demand — only when invoked | On demand — when selected |
-| Purpose | Project-wide conventions | Reusable task-specific knowledge | Specialized persona with tool restrictions |
+| Purpose | Project-wide conventions | Reusable task-specific knowledge | Specialised persona with tool restrictions |
 | Scope | Global context | Focused instructions for one task type | Full conversation takeover |
 | Best for | Coding standards, architecture rules | Repeatable workflows, generation recipes | Complex multi-step workflows |
 
diff --git a/tutorial/lessons/11-agent-delegation.md b/tutorial/lessons/11-agent-delegation.md
@@ -2,7 +2,7 @@
 
 ## What You'll Learn
 
-How Copilot CLI delegates work to specialized agents — including the powerful `/delegate` command that pushes tasks to a coding agent and creates pull requests automatically. You will see how built-in agents handle different types of work.
+How Copilot CLI delegates work to specialised agents — including the powerful `/delegate` command that pushes tasks to a coding agent and creates pull requests automatically. You will see how built-in agents handle different types of work.
 
 ## Concepts
 
@@ -15,7 +15,7 @@ Copilot CLI comes with agents that handle specific types of work:
 | **Explore** | Read-only codebase search. Fast, lightweight. Good for "find all uses of X" or "what does module Y do?" |
 | **Task** | Full-capability agent for complex, multi-step work. Can read, write, and run commands. |
 | **General-purpose** | The default agent you've been talking to. Balances exploration with implementation. |
-| **Code-review** | Specialized for reviewing code changes. Checks for bugs, style issues, and best practices. |
+| **Code-review** | Specialised for reviewing code changes. Checks for bugs, style issues, and best practices. |
 
 ### The `/delegate` command
 
@@ -48,7 +48,7 @@ This opens an interactive selector showing all built-in and custom agents. You c
 - **Parallel work** — Delegate tasks while you keep working on something else
 - **Focused context** — Each agent works in its own context, not polluting your conversation
 - **PR workflow** — `/delegate` creates a PR, so you review the output through your normal code review process
-- **Specialization** — Different agents are optimized for different tasks
+- **Specialisation** — Different agents are optimised for different tasks
 
 ### When to delegate vs do it yourself
 
@@ -68,7 +68,7 @@ Ask Copilot a broad question that touches multiple parts of the sample app simul
 
 > "Are there any inconsistencies between how tasks are validated in validators.ts vs how they're created in tasks.ts? Also check if the test coverage matches the actual API surface."
 
-Watch the output — you will see Copilot using agents to work in parallel, each with a focused scope. The results are synthesized back into a single answer.
+Watch the output — you will see Copilot using agents to work in parallel, each with a focused scope. The results are synthesised back into a single answer.
 
 After observing, try the `/agent` command to see what agents are available.
 
diff --git a/tutorial/lessons/13-git-workflow.md b/tutorial/lessons/13-git-workflow.md
@@ -12,7 +12,7 @@ When you ask Copilot to commit your changes, it doesn't just slap on a generic m
 
 1. **Runs `git diff`** — reads exactly what changed
 2. **Checks recent commit history** — matches your project's message style
-3. **Drafts a descriptive message** — summarizes the "why", not just the "what"
+3. **Drafts a descriptive message** — summarises the "why", not just the "what"
 4. **Stages and commits** — handles the git commands for you
 
 Try: `"commit my changes with a descriptive message"`
@@ -32,7 +32,7 @@ Copilot has a built-in code review command:
 /review
 ```
 
-This triggers the specialized Code-review agent, which examines your changes and provides feedback — checking for bugs, style issues, security concerns, and best practices.
+This triggers the specialised Code-review agent, which examines your changes and provides feedback — checking for bugs, style issues, security concerns, and best practices.
 
 You can also provide specific review instructions:
 
@@ -87,7 +87,7 @@ Pay attention to:
 1. Start with: "Add a JSDoc comment to the `createTask` function in `exercises/sample-app/src/tasks.ts` describing what it does, its parameters, and return value"
 2. After the edit is made, say: "commit my changes with a descriptive message"
 3. Watch the output — Copilot will run `git diff`, `git log`, and then `git commit` with a crafted message
-4. If there's no git repo initialized, Copilot will let you know — that's fine, the learning is in seeing the workflow
+4. If there's no git repo initialised, Copilot will let you know — that's fine, the learning is in seeing the workflow
 
 ## Completion Criteria
 
diff --git a/tutorial/lessons/14-session-management.md b/tutorial/lessons/14-session-management.md
@@ -2,7 +2,7 @@
 
 ## What You'll Learn
 
-How to manage Copilot CLI sessions across multiple tasks and days. Resume conversations, compress context, and keep parallel workstreams organized.
+How to manage Copilot CLI sessions across multiple tasks and days. Resume conversations, compress context, and keep parallel workstreams organised.
 
 ## Concepts
 
@@ -35,7 +35,7 @@ As conversations grow, the context window fills up. Copilot handles this automat
 
 This keeps you in flow without the hard reset of `/clear`.
 
-### Token visualization
+### Token visualisation
 
 **`/context`** — See exactly where your tokens are being used:
 
@@ -67,7 +67,7 @@ Sometimes it's better to start over than to correct course:
 
 **Practice session management commands.**
 
-1. Try `/context` to see your token usage visualization
+1. Try `/context` to see your token usage visualisation
 2. Try `/usage` to see your session statistics
 3. Think about when you'd use `--continue` vs `/resume`:
    - `--continue`: "I closed my terminal but want to pick up exactly where I left off"
@@ -78,7 +78,7 @@ Sometimes it's better to start over than to correct course:
 
 1. `/context` shows a visual breakdown — it's the quickest way to understand your token budget
 2. `/usage` gives you raw session stats
-3. `/compact` is your friend for long sessions — it summarizes without losing the thread
+3. `/compact` is your friend for long sessions — it summarises without losing the thread
 4. This is about building habits: use `/clear` between tasks, `/compact` when sessions get long, and `/resume` to pick up where you left off
 
 ## Completion Criteria
diff --git a/tutorial/lessons/15-programmatic-mode.md b/tutorial/lessons/15-programmatic-mode.md
@@ -68,7 +68,7 @@ Export a session for sharing or archiving:
 "lint:copilot": "copilot -p 'review changes vs main for typos and style issues'"
 ```
 
-**Fan-out processing** — analyze multiple files:
+**Fan-out processing** — analyse multiple files:
 ```bash
 for file in src/*.ts; do
   copilot -sp "summarize what $file does in one sentence"
diff --git a/tutorial/lessons/16-model-selection.md b/tutorial/lessons/16-model-selection.md
@@ -63,7 +63,7 @@ Configures multiline input for your terminal — useful if you write long prompt
 Choose a visual theme for the Copilot CLI interface.
 
 **Environment variables:**
-You can set default behaviors through environment variables in your shell profile.
+You can set default behaviours through environment variables in your shell profile.
 
 ### The `/init` command
 
@@ -90,7 +90,7 @@ This creates a `.github/copilot-instructions.md` file with sensible defaults bas
 
 1. `/model` or `/models` opens the model picker — try it to see what's available
 2. You can switch models mid-session without losing context
-3. `/theme` lets you customize the visual appearance
+3. `/theme` lets you customise the visual appearance
 4. `/init` is useful when you're setting up Copilot CLI for a new project
 
 ## Completion Criteria
diff --git a/tutorial/lessons/17-cli-tools-and-mcp.md b/tutorial/lessons/17-cli-tools-and-mcp.md
@@ -79,15 +79,15 @@ Here's a decision framework:
 
 Let's see Copilot use a CLI tool for data work. Ask Copilot:
 
-> "Use curl to fetch todos from `https://jsonplaceholder.typicode.com/todos?_limit=5`, save the response to `exercises/sample-app/api-response.json`, then analyze the data — how many are completed vs incomplete?"
+> "Use curl to fetch todos from `https://jsonplaceholder.typicode.com/todos?_limit=5`, save the response to `exercises/sample-app/api-response.json`, then analyse the data — how many are completed vs incomplete?"
 
 This demonstrates Copilot using `curl` — a non-code-editing CLI tool — to fetch real API data and work with it. Watch how Copilot runs the command, saves the output, and reasons about the JSON response.
 
 ## Hints
 
 - If you want to see what Copilot is doing step by step, ask it to explain each command before running it.
 - `curl` is pre-installed on both macOS and Windows 10+, so this should work on any modern system.
-- After Copilot saves the file, have it read back the JSON and summarize what it contains.
+- After Copilot saves the file, have it read back the JSON and summarise what it contains.
 
 ## Completion Criteria
 
diff --git a/tutorial/lessons/18-working-with-images.md b/tutorial/lessons/18-working-with-images.md
@@ -2,7 +2,7 @@
 
 ## What You'll Learn
 
-How to use images with Copilot CLI — debugging from screenshots, implementing from design mockups, and analyzing visual content.
+How to use images with Copilot CLI — debugging from screenshots, implementing from design mockups, and analysing visual content.
 
 ## Concepts
 
diff --git a/tutorial/lessons/19-graduation.md b/tutorial/lessons/19-graduation.md
@@ -11,7 +11,7 @@ You have worked through the core of Copilot CLI hands-on:
 - Used Shift+Tab to trigger planning mode and watched Copilot design an approach before writing code
 - Wrote and ran tests using Copilot's shell access
 - Created a custom agent for your own workflow
-- Watched Copilot delegate work to specialized agents
+- Watched Copilot delegate work to specialised agents
 - Understood how hooks automate workflows — and saw them in action
 
 ## Key Takeaways
@@ -60,7 +60,7 @@ If you hit these problems in real work, here's where to look:
 | "Endless back-and-forth refinement" | Stop. `/clear`. Use the "interview me" pattern to write a spec first. Put it in instructions. Start fresh. | L2, L7 |
 | "Copilot doesn't know about my whole project" | It does — Copilot CLI searches your entire codebase, not just open files. Point it at the right directory. Add architecture context to copilot-instructions.md. | L3-4 |
 | "I don't know which approach to use" | See the decision matrix in Lesson 7 — match your task type to the right strategy. | L7 |
-| "Context window fills up too fast" | `/clear` between unrelated tasks. `/compact "Focus on [topic]"` to summarize without losing the thread. Use `/context` to check token usage. Keep sessions short and focused. | L3 |
+| "Context window fills up too fast" | `/clear` between unrelated tasks. `/compact "Focus on [topic]"` to summarise without losing the thread. Use `/context` to check token usage. Keep sessions short and focused. | L3 |
 
 ## Where to Go Next
 
diff --git a/tutorial/lessons/20-test-planning.md b/tutorial/lessons/20-test-planning.md
@@ -2,11 +2,11 @@
 
 ## What You'll Learn
 
-How to use Copilot CLI to analyze a feature request, understand the existing codebase, and produce a structured test plan — the kind of artifact a QA engineer creates before any testing begins.
+How to use Copilot CLI to analyse a feature request, understand the existing codebase, and produce a structured test plan — the kind of artifact a QA engineer creates before any testing begins.
 
 ## Concepts
 
-QA work starts before anyone writes test code. When a new feature request arrives, the first step is to analyze the requirement, understand the affected code, and produce a test plan that covers:
+QA work starts before anyone writes test code. When a new feature request arrives, the first step is to analyse the requirement, understand the affected code, and produce a test plan that covers:
 
 - **Happy path** — the feature works exactly as described under normal conditions
 - **Edge cases** — unusual but valid inputs or states
@@ -37,14 +37,14 @@ Here is the feature request:
 
 Ask Copilot to:
 
-1. Analyze the feature request and the existing codebase (especially `@exercises/sample-app/src/tasks.ts`)
+1. Analyse the feature request and the existing codebase (especially `@exercises/sample-app/src/tasks.ts`)
 2. Produce a structured test plan at `exercises/sample-app/TEST-PLAN.md`
 3. The test plan should include at least 6 test cases with IDs, preconditions, steps, and expected results
 4. Cover happy path, edge cases, boundary conditions, and negative tests
 
 ## Hints
 
-1. Start with: "Read the feature request above and analyze `@exercises/sample-app/src/tasks.ts`. Then create a test plan at `exercises/sample-app/TEST-PLAN.md`"
+1. Start with: "Read the feature request above and analyse `@exercises/sample-app/src/tasks.ts`. Then create a test plan at `exercises/sample-app/TEST-PLAN.md`"
 2. If the plan lacks structure, ask: "Add test case IDs (TC-001, TC-002...) and include preconditions, steps, and expected results for each case"
 3. If coverage feels thin, ask: "What edge cases are we missing? What about empty strings, special characters, or very long search terms?"
 4. A good test plan typically has 6-10 test cases for a feature this size
diff --git a/tutorial/lessons/21-test-case-design.md b/tutorial/lessons/21-test-case-design.md
@@ -13,7 +13,7 @@ Two classic QA techniques help here:
 - **Equivalence partitioning** — divide inputs into groups that should behave the same way, then test one value from each group. For example, task priorities have three valid partitions (low, medium, high) and one invalid partition (anything else).
 - **Boundary value analysis** — test at the edges of valid ranges. If a title must be 1-100 characters, test with 0, 1, 100, and 101 characters.
 
-Copilot CLI can analyze your source files and existing tests in one pass, identify which modules lack coverage, and generate test cases using these techniques.
+Copilot CLI can analyse your source files and existing tests in one pass, identify which modules lack coverage, and generate test cases using these techniques.
 
 ## Exercise
 
@@ -27,15 +27,15 @@ The sample app has four source modules in `exercises/sample-app/src/`:
 
 Ask Copilot to:
 
-1. Analyze all source files in `@exercises/sample-app/src/` and the existing test file `@exercises/sample-app/tests/tasks.test.ts`
+1. Analyse all source files in `@exercises/sample-app/src/` and the existing test file `@exercises/sample-app/tests/tasks.test.ts`
 2. Identify which modules have no test coverage
 3. Create `exercises/sample-app/TEST-CASES.md` with detailed test cases for the untested modules
 4. Apply equivalence partitioning and boundary value analysis where appropriate
 5. Each test case should specify: the function being tested, input values, expected output, and which technique it applies
 
 ## Hints
 
-1. Start with: "Analyze all source files in `@exercises/sample-app/src/` and the test file `@exercises/sample-app/tests/tasks.test.ts`. Which modules have no test coverage?"
+1. Start with: "Analyse all source files in `@exercises/sample-app/src/` and the test file `@exercises/sample-app/tests/tasks.test.ts`. Which modules have no test coverage?"
 2. Then: "Create `exercises/sample-app/TEST-CASES.md` with detailed test cases for the untested modules. Use equivalence partitioning and boundary value analysis."
 3. Look for: `formatters.ts` functions (formatTask, formatTaskList, formatPriority, formatDate), `utils.ts` functions (capitalize, truncate, groupBy), and `validators.ts` functions (isValidTitle, isValidEmail)
 4. A thorough analysis should catch the formatTaskList 0-indexing bug
diff --git a/tutorial/lessons/22-automated-test-generation.md b/tutorial/lessons/22-automated-test-generation.md
@@ -27,7 +27,7 @@ Ask Copilot to:
 4. If tests fail, determine whether the failure is a test bug or a code bug
 5. Fix the `formatTaskList` bug in `src/formatters.ts` (it uses 0-based indexing instead of 1-based) and verify all tests pass
 
-If you haven't completed Lesson 21, you can still do this exercise — just ask Copilot to analyze `@exercises/sample-app/src/formatters.ts` and write comprehensive tests for it.
+If you haven't completed Lesson 21, you can still do this exercise — just ask Copilot to analyse `@exercises/sample-app/src/formatters.ts` and write comprehensive tests for it.
 
 ## Hints
 
diff --git a/tutorial/lessons/24-qa-track-graduation.md b/tutorial/lessons/24-qa-track-graduation.md
diff --git a/tutorial/validators/validate-13.sh b/tutorial/validators/validate-13.sh
