Phrasal Verb: Fill In
to complete a form
Examples
- Fill in this form.
Key rules
- Fill in means complete a form or temporarily replace someone
- It is separable: fill in the form or fill the form in
- With a pronoun, the pronoun goes in the middle: fill it in
- In American English, "fill out" is more common for forms
Common mistakes
- Fill up the form → Fill in the form
💡 Tip: "Fill up" means make something completely full, which is a different meaning.