How do you put half in a sentence?

Answer 1

It depends on how you are using the word "half".

Most of the time it is used as an adjective.

If the word is being used as part of a mixed numeral, then the word is preceded by "and a": "I used three and a half cups of flour in the cake."

If the word is being used to denote 50% of a single countable item, then you may use "a half" or "half a(n)", but never "a half a(n)":

"We will be there in half an hour."

"We will be there in a half hour."

It is never correct to use "We will be there in a half an hour."

If the word is being used to denote 50% of an uncountable or plural countable item, then the word is followed by "the" or "of the":

"Jane used up half the napkins during dinner."

"Bob lost half of his marbles in the game."

Idiomatically, there exists "half and half", which is approximately 50% cream and 50% milk. This is a noun and is used the same way as the word "milk" with nothing extra needed: "I poured half and half in my coffee."