"must" is an example of a defective verb. It has only the present tense. To get the meaning of the past perfect tense of must, you have to say something like"had been required" or "had been obligated".
the past tense of am is was and the past tense of has is had
The past tense of "has" is "had" and the past tense of "have" is "had."
Was and were are both the past tense of be. The present tense is: I am he is you are they are The past tense is: I was he was you were they were
"will be" is the future tense of "be". The past tense of "be" is "was/were".
The past tense of "she do" is "she did."
The word "were" is past tense. It is the past tense of the verb "to be."
The past tense of "will" is "would" and the past tense of "be" is "was" or "were" depending on the subject (singular or plural).
HAD is the Past Tense of TO HAVE.
The past tense of "am" is "was" and the past perfect tense of "has" is "had."
The past tense of "have" is "had."
The past tense of "you will not" is "you would not."