find,
fined

Did you find your book?

Yes, but I was fined because it was overdue.

fir,
fur

Fir trees are evergreen trees.

Polar bears have thick fur coats.

for,
four

You may eat the kiwis for a snack.

The four of you may also share the crackers.

good,
well

Ling looks good in that outfit.

(Good is an adjective modifying the noun “Ling.”)

It fits her well.

(Well is an adverb modifying the verb “fits.”)