fromEnglish Grammar Today
Finite verb forms show tense, person and number (I go, she goes, we went, etc.):
Shewas waitingin the room before hecamein.
Doesyour brotherknowmy brother?
The night before hehadto leave, theysaton the small sofa in the living-room andlookedat old family photos.
Aren’tyou a bit late?
Non-finite verb forms do not show tense, person or number. Typically they are infinitive forms with and withoutto(e.g.to go, go), -ingforms and -edforms (e.g.going, gone):
She tiptoed round the house so as notto wakeanyone.
You need to paint the whole cupboard,startingfrom the bottom.
[from a biography]
Takenprisoner by the British in December 1776, he was held in New York City for a year …
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Clauses: finite and non-finite