Both mean 'quedar bien', but one is about size and the other about style or what looks good on you.
"Fit" describes that something is the right size or shape: clothing fits you. Also that someone is physically fit or well-suited for a task.
These shoes fit perfectly.
The jacket does not fit. It is too small.
Does this key fit the lock?
"Suit" describes that something works for you or is convenient in a broader sense. An offer "suits" you if it fits your needs or style.
That color really suits you.
A career in medicine would suit her perfectly.
Does Tuesday suit you for the meeting?
Common mistake
"That color fits you" is wrong when meaning it is flattering: "fit" is for physical size and shape. Color and style "suit" (look good on you). Size can "fit"; color "suits".
Trick to remember it
Quick rule
Did you know?
"Suit" as a noun means a business suit, wetsuit, or swimsuit. This gives a useful clue: when something "suits" you, it fits you like a well-cut suit, not in exact size but in style and purpose. The expression "follow suit" (to follow someone's example) comes from card games, where you follow the suit (card type) that was played.
Exercise 1 · Pick the right one
These shoes don't _____ me. They are too small.
Exercise 2 · Pick the right one
That colour doesn't _____ her. It makes her look pale.
Exercise 3 · Form the word
"Above" is at a higher level without contact; "over" implies covering, movement, or crossing.
"Actually" corrects or contrasts an assumption; "really" intensifies or confirms.
'Currently' means 'at the present time'; 'actually' means 'in reality', not 'nowadays'.
'Adopt' means to take something on as your own; 'adapt' means to adjust to something new.
Bryan López
Founder of SpeakUP Academy