The past tense is frequently brought into use in English grammar, for an entire gamut of human experiences, emotions and events are based in the contextual past.
Past Tense is used to denote activities that happened or started or ended or continued in the past.
It is also used to talk about hypothetical situations (Example: It might be a risky venture) or for the sake of maintaining decorum. (Example: I hoped you would be able to help me)
Depending on the contextual differences, Past Tense may be classified into four categories:
1. Simple Past Tense:
Structure: Subject +V2.
Example: I ate an apple.
a. It is used to indicate an activity that started and ended in the past.
Example: I went for a walk.
b. It is the only form of past tense that is sued with an adverb of time that is in past.
Example: Yesterday, we went to watch a movie.
2. Past Progressive / Continuous
Structure: Subject + was/were +V4.
Example: I was sleeping.
a. This indicates a past activity that is still in progression and not completed.
Example: I was trying to do my homework.
b. Describing an activity in the past which was interrupted by another activity in the past.
Example: I was watering my plants when I noticed something suspicious.
c. It is also used to denote an activity that continued for a long period before being interrupted by another activity, using the word ‘while’.
Example: I burned my hands while I was cooking dinner.
d. Describing a past activity that continued for a long time in the past and in all probability may still be in progression.
Example: Many patients were complaining of severe symptoms of dengue last month.
3. Past Perfect
Structure: Subject + had + V3.
Example: I had eaten.
a. When more than one action is mentioned that took place in the past, Past perfect is used to denote the activity that happened first and Simple Past is used to denote the activity that followed it in succession.
Example: The train had left the station before I arrived.
b. Describe a past activity that was finished in a specified time period.
Example: The workers had finished the building within the stipulated time period.
c. While describing two activities, both in the past , Past perfect is used to denote the
Shorter action and Past Continuous to denote the longer action.
Example: I had eaten my dinner while watching television.
4. Past Perfect Continuous / Progressive Tense
Structure: Subject + had + been + V4.
Example: The workers had been building the bridge since last 10 years.
a. Describing an activity that started in the past and is still in continuation and have not been completed.
Example: I had been visiting London for a long time now.
b. To indicate an activity that started in the past, was in continuation and overlapped with other activities which started much later in the past.
Example: I had been working on my thesis for about 5 years when I met Sam.