If you only ever use AI for two things, these are the two. Rewriting is where the model is at its most reliable, because you gave it the facts and it only has to change the tone. Summarising is the same trick in reverse: the facts are in the text, the model just has to choose which ones matter.
Win 1: rewrite an email
The mistake beginners make is asking for a rewrite without saying who it is for or what tone you want. Say both. Say the length. If there is one fact that must survive — a date, a number — say it must be in the first line.
Try it
Rewrite a rough message as a friendly professional email
- Did it work? Friday is in the first sentence, it is under 100 words, and it did not invent a reason you never gave (a sick child, a system outage).
- If not: add one line to the prompt — *"Do not add any reasons or details that are not in my message."* That single instruction fixes most rewrite problems.
Win 2: summarise something long
Ask for a number of bullets. Open-ended "summarise this" gets you a paragraph that is nearly as long as the original. Three bullets forces the model to choose, and choosing is the whole point of a summary.
Try it
Summarise a council notice in three bullets
- Did it work? Three bullets, and the 30 September deadline survived. That deadline is the one thing in the notice that costs you money if you miss it, so it is the test.
- If not: tell the model what matters — *"Prioritise anything with a deadline or a fee."* A summary is only good relative to what you care about.
| Ingredient | Rewrite | Summarise |
|---|---|---|
| Who it is for | my manager | a resident who has to act |
| Length | under 100 words | exactly 3 bullets |
| What must survive | the Friday deadline, first sentence | every date and action |
| What must not happen | no invented excuses | no dropped deadlines |
Knowledge check
Your email rewrite came back with a line about "a family emergency" you never mentioned. What is the fix?