We use 'longer' to say that one thing has more length or lasts more time than another. It is the form of 'long' that compares two things.
This road is longer than that one.
She read a longer book yesterday.
'Longer' as an adverb talks about time continuing. It often appears in negative or question sentences showing that more time is not used or is asked about.
I don't live here any longer.
Do you want to wait any longer?
Sometimes 'longer' is used as a noun to describe someone who stays late or works extra time. This is an informal use mostly in British English.
He is a longer at the office today.
She was the last longer in the shop.
In cricket, a 'longer' is a bowling term for a ball pitched nearer to the batsman than usual. It can affect how the ball is played.
The bowler bowled a longer to confuse the batsman.
He saw the longer and moved quickly.
In tailoring, a 'longer' can mean an extra length of fabric added to clothing for fitting or extending parts. It is informal and used in textiles.
The tailor added a longer to the sleeve.
She requested a longer for her dress.
'Longer' shows the '-er' suffix used to make comparatives in English. It changes 'long' to 'longer' to compare two things.
Add '-er' to make 'longer' from 'long'.
Faster and longer are comparative forms.