Note: Paid subscribers can download all four complete lesson packages at the end of the post.
For thirty years I’ve been writing ESL materials. For the past few months, AI has been writing them with me — to my exact standards, in my exact formats. Not because the models suddenly got smarter (though they have). Because of a small, unglamorous file called SKILL.md.
This Week’s Lessons
Before we get to the SKILL.md pack, here are this week’s new and updated lessons:
Describing Appearance (high elementary and above) — new
The Consumer Experience (high elementary and above) — makeover
Decarbonization (pre-intermediate and above) — new
SKILL.md
If the name makes your eyes glaze over, stay with me. SKILL.md sounds technical, and that’s exactly why most teachers haven’t touched it. But it isn’t code. It’s a plain text file written in plain English — instructions to the AI about how you like things done. Think of it as a rubric for the AI: “When I ask for a vocabulary worksheet, here are 15 words, here’s the layout, here’s the answer key format, here’s what to avoid.” The AI reads it, follows it, and stops producing the generic slop that makes most AI-written worksheets unusable in a real classroom.
That last bit is the whole point. Generic AI output is fine for a one-off. It’s useless if you’ve spent years developing format standards — brainstorms, vocabulary sets, plain-text answer keys, SVG files you can edit. A SKILL.md flips the AI from generalist to specialist. You stop fighting it. You start collaborating with it.
And here’s the part most people miss: SKILL.md isn’t locked to one platform. It’s an open standard. The same file works in Claude, ChatGPT and Gemini. The same idea — a plain English instruction file the AI reads before it does anything — is being adopted across the major AI tools. Write it once, use it everywhere. Your formats, your style, your standards — they travel with you.
The SKILL.md Starter Pack
Below the paywall, I’m sharing five of the SKILL.md files I actually use every week — the ones behind the worksheets you’ve been downloading from this Substack. Drop them in, point your AI at them, and you’ll skip the months of trial and error it took me to fine-tune them.
A note on formats: Three of these skills produce HTML worksheets you can open in any browser and print straight to PDF — no extra software needed. The other two produce SVG files, which open for free in Inkscape (Mac, Windows, Linux) or OmniGraffle on Mac. If you only want to print, your browser or Preview will convert SVG to PDF in one click.
1. W3 — Classroom Discussion Quiz Creator (HTML) A short classroom dialogue plus multiple-choice comprehension questions, formatted as a printable HTML quiz. Also produces an audio-ready script with pause and emphasis cues for recording. The fastest way to turn any topic into a listening lesson.
2. W5 — Vocabulary Exercises (HTML) Two-part worksheets: multiple-choice definition matching plus gap-fill sentences, with a clean answer key. The classroom workhorse — useful for every vocabulary set you’ll ever teach.
3. W10a — Pronunciation Exercises (HTML) “Circle the word” listening discrimination plus “Syllable stress” practice, with answer keys and audio-ready word lists. The skill that fills a gap most ESL textbooks ignore.
4. W1 — Brainstorm Visual Organizer (SVG) Turns any topic into a colourful mind-map worksheet: a central idea, surrounding category circles, and a scrambled word cloud for students to sort. The fastest way to open a new unit.
5. W11 — Graph & Diagram Visualization (SVG) Generates a chart, graph, or diagram on any topic plus six comprehension questions. Hits data literacy, critical thinking, and reading-for-detail in one worksheet. The most “modern” skill in the pack.
