Grammar tips, Hollywood style.
When Does "Grown Up" Need a Hyphen?
"Grow up" is a phrasal verb and does not need a hyphen:
Oh, stop being a baby and grow up!
"Grown up" can be the past participle of "grow up," but it can also be a noun or an adjective; when it is, it needs a hyphen:
Always hold a grown-up's hand.
The grown-ups were whispering in the other room.
Read more about hyphens here.
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