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 perfect tense is used to refer to an action that happened in the past before another action that happened in the past.
To form the past perfect tense, you should follow this structure:
Some examples:
Formally, it is the combination of the past perfect tense of "to be" with the present participle of the principal verb for which the tense is formed. Example, with principal verb "go": "I had been going awry frequently until I got a global satellite positioning system for my car."
Existed is the past tense. The past perfect tense is had existed.
The past perfect tense of hope is had hoped.
The past tense of "bleed" is "bled." The past perfect tense of "bleed" is "had bled."
The past tense of sit is sat; the past perfect tense is had sat.
present tense past tense future tense present perfect tense past perfect tense future perfect tense present progressive tense past progressive tense future progressive tense present perfect progressive tense past perfect progressive tense future perfect progressive tense
Perfected is the past tense of perfect.
"Had been" is the past perfect tense of be.
The past perfect tense of 'get' is 'had gotten'
The past perfect tense of do is had done.
The past perfect tense of borrow is "had borrowed."
The past perfect tense of "think" is "had thought."
The past tense of paint is painted. Had painted is the past perfect tense.