Question

Explain three instance in which apostrophes

used to indicate omission provide an example for each instance

Answer 1

They can be used to show omission of numbers, like in a year. For example, instead of writing "2018" you could say '18.

They are used to show omission in a contraction. So, instead of saying "let us" you would say "let's"
Finally, it's used to make words shorter. For example, instead of saying "about" you could say " 'bout"