We use Present Perfect Simple for permanent situations or for longer time period and we prefer Present Perfect Continous for temporary situations or short time period.

I've lived in Ahmedabad for six years, (this is my permanent home).
I've worked for this company for ten years, (it's my permanent job)
I've been living in Delhi for six months, (but my usual home is in Ahmedabad)
I've been working here for a month, (a comparatively short time)

But it is often possible to use either the Present Perfect Continuous (to put emphasis on the length of time) or the Present Perfect Simple.

I've been teaching English for twenty years, or I've taught English for twenty years.

Simple past tense Session-1

Simple past tense Session-1

We usually use the short forms (wasn't/weren't] when we are speaking or writing a friendly letter:

Anila wasn't at home yesterday.

We use was and were to talk about the past:

I was a student of College of Science from 1991 to 1994.
She was swimming champion. (not now)
It was very hot last August.
They were at the club until midnight.

We use there was.../there were:., to talk about something in the past .

There was a small party in the school last Sunday.
There was a small pond in the garden.

Simple past tense Session-2

Simple past tense Session-2

We use it when we are talking about a particular time in the past:

One hour ago/Two years ago/Last night/Yesterday/Last month

Positive : Subject + 2^nd form of the verb + Object

Negative : Subject + did not ( didn’t) + 1^st form of the verb + Object

Questions : Did + Subject+ 1^st form of the verb + Object

I went to school yesterday.
I didn’t go to school yesterday.
Did you go to school yesterday ?