Translation guide
The English word 'cap' has several distinct meanings. This guide covers the most common ones for learners: headwear, a lid or cover, an upper limit, and a few other uses. Each meaning is presented with natural Japanese expressions.
A soft, close-fitting hat, often with a visor, like a baseball cap.
A removable cover for a bottle, pen, container, etc.
Loanword used for bottle caps, pen caps, and similar small covers.
A maximum amount, number, or restriction.
To do something better or more impressive than before; to finish or complete something in a notable way.
To put a cap or cover on something, or to cover the top of something.
To put a lid on something.
キャップ is mainly for small, often screw-on or snap-on covers (bottles, pens). ふた is for larger lids (pots, jars, boxes). Using キャップ for a pot lid sounds unnatural.
帽子 is the general word for any hat. キャップ specifically means a baseball-style cap. If you're not sure, use 帽子.
I bought a new cap.
He's wearing his favorite baseball cap.
I lost the cap of my pen.
Please close the bottle cap tightly.
General word for lid or cover. Used for pots, jars, boxes, etc. Not typically used for pen caps.
Please take the lid off the pot.
Kanji for ふた. Same meaning but more formal/written.
Open the lid of the jar.
Standard word for upper limit or maximum.
Is there a cap on the number of participants?
Set a cap on the budget.
Restriction or limit. Often used in rules or regulations.
Please observe the speed cap.
Loanword used in business or technical contexts for a cap on spending, etc.
Put a cap on expenses.
To finish off, to wrap up. Often used for ending an event or story in a satisfying way.
His speech capped off the meeting.
To exceed, to surpass. Used when one thing is greater than another.
This year's sales capped last year's.
Please cap the pot.
To put a cap on (e.g., a pen or bottle).
Please cap the pen.