Past of mustn't

For this meaning of have, do is needed:

I don't have to do my homework.
I didn't have to do my homework.
Do you have to do your homework?
Did you have to do your homework?

CB

Present=have to,negative= don't have to,past = had to,past negative = didn't have to

Present = must,negative = mustn't,past = had to,what about past negative ?,is it didn't have to also?

I found in a book these examples:

You must clean the house = obligation in the present

You mustn't clean the house = obligation n

everlastinghope You weren't allowed to clean the house = you were obliged not to do the cleaning(can we say,you didn't have to clean the house ?)

The meaning is completely different, as discussed above.

"You didn't have to do it" means th

Avangi
"mustn't" doesn't have a past, nor does "must."

Try to visit this website : http://forum.wordreference.com/showthread.php?t=32031 where it's said that the p

Of course there's a way to say it, but it seems absurd to me to call A the past tense of B when they're not even derived from the same word. Any fool can write a book.

So,is it correct to say " I didn't have to"instead o

everlastinghopeSo,is it correct to say " I didn't have to"instead of "wasn't allowed" ?

No. These two mean completely different things.

When you negate must, you negate the following proposition. An obligation or requirement still exists.

You must [stop at a red light]. (obligation: to do something)

You must [not dri

I mustn't do the cleaning;Past I wasn't allowed to do the cleaning. - everlastinghope

It's too confusing and I'm still not conviced because what drives me mad,is to find one thing in a book ( New Headway),and another thing in some websites.

Thanks for you all,anyway.

It comes down to definitions.
What do you mean by "The past tense of X is Y" ?
Are you referring to words, or expressions?

The past tense of "escape" is "got away." (true or false?)

Everlastinghope:

(1) Today when my wife comes home, I must not tell her what the doctor said, because the news would upset her if I told her.

(2) Yesterday when my wife came home, I was obliged not to tell her what the doctor had said, because the news would have upset her if I had told her.