Explanation

Hard is an adjective.

Hard means difficult.

Hard means مشکل 

Positive degree: Hard

Comparative degree: Harder 

Superlative degree: Hardest 

Explanation

This sentence belongs to Past Indefinite Tense.

Active Voice: He helped me. 

Passive Voice: I was helped by him. 

Explanation

The word Knowledge has no plural form.

Knowledge is the correct form.

Knowledge means علم 

Explanation

She sells sea shells by the sea shore is an example of Tongue Twister.

Tongue Twister: a word, phrase, or sentence difficult to articulate because of a succession of similar consonantal sounds

Explanation

• Period (.)
• Comma (,)

• Colon (:)

• semicolon (;)

• Question mark (?)

• Exclamation (!)