Meaning question

[JbhB682]

Hi Experts --

Just wondering, from a meaning perspective -- what is the difference between a sentence in the past tense vs. a sentence in the past perfect vs sentence in present perfect

example
-- Yesterday, I completed the work

vs

-- Yesterday, I Had completed the work

vs

-- Yesterday, I HAVE completed the work


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What is the difference in meaning between the 3 sentences -- in terms of meaning or effects specifically ?

[Sage Pearce-Higgins]

That's a big question! Verb tenses have many uses, and I can't possibly describe all of them here - check out the verbs chapter in the SC strategy guide.

However, in this brief context, only the first sentence is correct. When we state a specific time an event took place in the past, we need to use the past simple (I completed).

Here are some samples of the other tenses:

I had completed the work by yesterday. (Past perfect - finished before a time in the past)

Look! I have just completed the work. (Present perfect - recently finished activity)