Won't is the contraction of will not. According to my dictionary it was first recorded mid-15th century as wynnot, later wonnot (1584) before the modern form emerged 1667.
It will.
Haven't is the contraction of have not.
contraction made from the two words you will: you'll
Let's is the contraction of the two words 'Let us'
Contraction word made from the words they and are is they're.
The two words that make up the contraction "can't" are "cannot."
"who" and "will" make up the contraction "who'll."
It will.
"you" and "would" make up the contraction "you'd."
"You" and "would" make up the contraction "you'd".
It is
You are.
Does not.
will + not
"Weren't" is a contraction. It is composed of the words "were" and "not".
"Let us" combine to form the contraction "let's".
Won't is a contraction of will not.