Meaning trap
fill in
complete a form
to write the necessary information on a form or document.
Don't mix these meanings
Same phrase, different job.
to write the necessary information on a form or document.
Another meaning of 'fill in' is 'substitute for someone'; compare the examples to keep the meanings separate.
Hear it in context
Notice where the phrase sounds natural.
Please fill in this application form before your interview.
In my country, when you open a bank account, you have to fill in several forms with your personal details.
Fix the pattern
One small grammar move makes it sound right.
Not: Please fill the form.
Say: Please fill in the form. / fill out the form.
For forms, use 'fill in' (BrE) or 'fill out' (AmE) — bare 'fill' means make full.
Which sounds natural?
Tap the one a native speaker would say.
'Fill in' is what everyone says for completing a form (BrE); the formal version is a bureaucrat's note.
Build natural chunks
Words that usually travel with it.
fill in + form
- a form
- the blanks
- your details
- an application
Don't confuse it
Related
Other meanings and phrases to compare.
- fill in (substitute for someone) — Another meaning of 'fill in' is 'substitute for someone'; compare the examples to keep the meanings separate.