Incorrect: She likes to feed the poors.

Correct: She likes to feed the poor.

Incorrect: He is working for the blinds.

Correct: He is working for the blind.

Expressions like the poor, the blind, the deaf etc., are always plural. We don’t have to make their plural forms by adding –s to them.

Incorrect: I told these news to my father.

Correct: I told this news to my father.

News is a singular uncountable noun. Therefore it has to be used with a singular determiner.

Incorrect: The teacher gave us many advices.

Correct: The teacher gave us some advice.

Advice is an uncountable noun. It does not have a plural form. The determiner many is only used with plural countable nouns.

Incorrect: I have a five dollars note.

Correct: I have a five dollar note.

Incorrect: She has bought two dozens apples.

Correct: She has bought two dozen apples.

Incorrect: I saw many deers in the jungle.

Correct: I saw many deer in the jungle.

The nouns sheep and deer have identical singular and plural forms.

Incorrect: Bring me some bloating.

Correct: Bring me some bloating paper.

Incorrect: The boy is in the boarding.

Correct: The boy is in the boarding house.

Incorrect: Please put your sign here.

Correct: Please put your signature here.

Incorrect: She is my cousin sister.

Correct: She is my cousin.