When do you put a in a sentence?

Answer 1

Using "a" in a sentence can be confusing at times, here are some examples;

A cat was sitting on a window sill as I walked by.

My family and I are going going on a picnic.

The cow is getting a drink of water. - note; you use "a" because the word after "a" (drink) does not start with a "vowel" words a,e,i,o,u, - ex. The horse is eating an apple. We use "an" instead of "a". It softens the sentence and makes it flow nicely as we speak it.

Answer 2

The word "a" is an indefinite article used before a singular noun that is unspecified or introduces a new noun to the conversation. It is placed before a noun to indicate that the noun is referring to one member of a group of similar objects or individuals.