Explanation

The preposition since is used to show point of time e.g. Since 2015, Since May etc.

 The preposition for is used to show period of time e.g. For 3 days, For one hour etc.

Explanation

They were playing football means وہ فٹبال کھیل رئے تھے۔

Explanation

Here 'Yesterday' shows something happened in the past.

Second form of a verb is used in Past Indefinite Tense.

Met is the second & third form of Meet. 

Explanation

Here 'Next Weakened' shows something will happen in the future.

Will + first form of a verb is used in Future Simple Tense.

Explanation

This is a sentence of Past Indefinite Tense in Passive Voice.

Formula: Object + was/were + third form of a verb + by + Subject.

Explanation

This is a sentence of Present Perfect Continuous Tense.

Formula: Subject + has/have + been + verb + ing + object

Explanation

Something was happening: verb + ing (making noise)

Something happened: second form of a verb (entered) 

Explanation

The word 'for' is used to show a period of time, be it in the past, present or future.

Explanation

resist adding

Explanation

Here 'last morning' shows something happened in the past.

Was is used with a singular subject (Abullah) in the past tense.