Prompting Basics
Writing instructions that AI can follow.
A prompt is an instruction you give to AI. It's not just about what you ask, but how you ask it.
The Key Insight
You're not "chatting" with AI — you're programming it with natural language.
Every prompt is a tiny program that tells the AI:
- What role to play
- What task to perform
- What constraints to follow
- What format to output
Good vs. Bad Prompts
| Bad Prompt | Good Prompt |
|---|---|
| "Fix my document" | "Fix grammar and spelling errors in this document. Preserve technical terms unchanged." |
| "Make this better" | "Improve clarity and flow. Keep my voice and style." |
| "Summarize this" | "Summarize in 3 bullet points, focusing on the main argument." |
The difference: specificity, constraints, and clear expectations.
A Simple Framework
When writing prompts, think in layers:
| Layer | Question | Example |
|---|---|---|
| Role | Who is the AI? | "You are a proofreader for academic writing" |
| Task | What should it do? | "Check this document for errors" |
| Constraints | What are the rules? | "Don't change technical terms" |
| Format | How should it respond? | "Present changes in a table" |
Not every prompt needs all layers. But knowing the framework helps when simple prompts don't work.
Example: Grammar Check
A basic prompt:
Check the grammar in this document.
A better prompt:
You are a proofreader for academic writing.
Check this document for:
- Grammar errors
- Spelling mistakes
- Awkward phrasing
Rules:
- Don't change technical terms
- Preserve the author's voice
- Keep citations in their original format
Output:
Present each change in a table with columns:
| Original | Suggested | Reason |
The second prompt is longer but produces more consistent, useful results.
Common Mistakes
1. Too Vague
❌ "Make this better" ✅ "Fix grammar errors and improve clarity, but preserve my voice"
2. Over-Constraining
❌ "Only use words from this list..." ✅ Let AI use its judgment within reasonable bounds
3. No Format Specified
❌ "Analyze this document" ✅ "Analyze this document. List 3 key themes with supporting quotes."
Iteration
Prompts rarely work perfectly the first time. The process:
- Write an initial prompt
- See what AI produces
- Identify what's wrong
- Adjust the prompt
- Repeat
This is normal. Even experts iterate on their prompts.
Going Deeper
- Prompt Engineering Guide — comprehensive resource
- Anthropic's Prompt Library — official examples
- Learn Prompting — free course
Next: Understand Agents — AI that takes action, not just responds.