We will use the verb 'eat' (an irregular verb) to illustrate the difference between past tense and past perfect tense.
Introductory grammar notes:
The past tense of eat is ate. The past participle (used for forming the 'past perfect') is eaten.
PAST TENSE: The 'past tense' ('Past Simple') form is used to say what happened/finished in a time before now.
e.g. 'Yesterday I ate three big bars of chocolate.'
PAST PERFECT TENSE: The 'past perfect' tense is used to show that an action had already finished before something else that also happened in the past. In other words, there are two events in the past, and one happened before the other.
PAST PERFECT FORM: had + (past participle).
e.g., 'I was very ill yesterday afternoon. I think this was because I had eaten three bars of chocolate at lunch time!'
Notice that two things are mentioned as happening yesterday. First (in time), I ate three bars of chocolate, and later I was ill.
In this case there is possibly a causal relationship between the two events, but this isn't always so when the past perfect is used.
e.g. 'I had only just put the washing out when it started to rain!'
It is extremely unlikely that putting the washing out to dry actually caused it to rain! However, notice that there are again two events, one following the other, i.e. (i) the washing was put out. (ii) it started to rain.
SUMMARY OF THE DIFFERENCE BETWEEN PAST (SIMPLE) TENSE AND PAST PERFECT TENSE
- The 'past simple' relates to a finished event in the past.
- The 'past perfect' form (had + past participle) is used when there are two events in the past, one of which occurred before the other.
