DEFINITION OF PAST TENSES IN ENGLISH GRAMMAR WITH EXAMPLES

PAST TENSE

1) Simple Past Tense-

Indicates an action took place before the present moment and that has no real connection with the present time. 
For example, "He danced in the function." (The action took place in the past, is finished and is completely unrelated to the present)
                         "He flew to London yesterday."
Note
a. The verb 'flew' is an irregular verb which does not take 'ed' in the past tense like regular verbs.
b. The form of Simple Past Tense is - verb + ed

2) Past Perfect Tense-

Indicates an action in the past that had been completed before another time or event in the past.
For example, "He had exercised before it started to rain."
                         "He had slept before I came back from the market."
Note
a. The form of Past Perfect Tense is- had + verb (past participle form or the 3rd form of the verb)

3) Past Continuous Tense-

Indicates an action going on at some time in the past or an action in the past that is longer in duration than another action in the past.  
For example, "It was getting darker."
                        "The light went out while theywere reading."
Note
a. The form of Past Continuous Tense is- was/were + verb + ing
 

4) Past Perfect Continuous Tense-

Indicates an action in the past that took place before another time or event in the past and continued during the second event/time point in the past.
For example, "At that time, he had been writing a novel for two months."
                         "He had been exercising when I called." 
Note
a. The form of Past Perfect Continuous Tense is- had + been + verb + ing