had - past tense of has and not necessarily a clue word for the past perfect tense?

[Yura Reiri]

So basically, what I am asking about here is if 'had' could actually be the past tense of 'has' and if it could stand alone even without the other past action.

Example:

She had suffered enough/ She had been waiting for years until you came. ( the 'has' was replaced with 'had'. Can I use this one? I've been meaning to use it this way.)

OR

She had suffered enough before you came. ( past perfect )

You see, I'm trying to write a story. I'm narrating things that happened in the past so I wanted everything to be in the past tense including 'had'. But my teacher told us that if we used 'had', then it should be with another past action.

Please help me. Thank you.

[Raymott]

So basically, what I am asking about here is if 'had' could actually be the past tense of 'has' and if it could stand alone even without the other past action.
Yes, you can use the verb "to have" and all of its forms as a main verb. It's not just an auxiliary verb.

Example:

She had suffered enough/ She had been waiting for years until you came. ( the 'has' was replaced with 'had'. Can I use this one? I've been meaning to use it this way.)

OR

She had suffered enough before you came. ( past perfect )

You see, I'm trying to write a story. I'm narrating things that happened in the past so I wanted everything to be in the past tense including 'had'. But my teacher told us that if we used 'had', then it should be with another past action.

Please help me. Thank you.

No, what your teacher meant was that when you use the past perfect tense ('had' as an auxiliary verb) then it should be used with another past action.

[Yura Reiri]

Oh, I see. Thank you so much!