Same in french two answers in english?

Checking 2 online translators (deepL and google), “should have” seems to be the translation they both show for these 2 different tenses. That is not my understanding from the lesson here, or others I have come across where the difference between future anterior and past conditional is as noted below. 

In the case of “tu” specifically, the forms are different in writing and in pronunciation :

Tu auras dû (infinitive) - you will have had to ()

Conjugate vouloir/pouvoir/devoir in the future perfect in French (Le Futur Antérieur)%252Fsearch%253Fs%253DFuture%2526model%253Dcompetency%2526ispg%253D686751%2526page%253D2

Tu aurais dû (infinitive) - you should have ()

Conjugate devoir in the conditional past in French = should have (Le Conditionnel Passé)%252Fsearch%253Fs%253DPast%252Bconditional

In general, I use but don’t trust any online translator, although I think deepL is better than google.

Hi Gordon,

I agree that Deepl is one of the best online translators, but should be used with caution.

My analysis of the grammar suggests:-

Tu auras dû  -->  You will have had to ....

Tu aurais dû  --> You would have had to ....

Tu devrais avoir dû  --> You should have had to  ...

If one puts the grammatical analysis above into Deepl all are translated as "should have"

So there you have it ----

Jim

I agree with Maarten:

Tu auras dû renoncer à ton rêve. -- You will have had to give up on your dream. (future perfect tense)
Tu aurais dû renoncer à ton rêve. -- You should have given up on your dream. (past conditional)

Hi Gordon,

I've been pondering this question for some days.

You'll see that two of the regular contributors agree with "aurais dû" as the translation for "should" and this is consistent with Deepl (note my comment about translators above.)

But we have to be careful about the context here. 

"Tu auras dû renoncer à ton rêve."   What does this sentence convey?

Does it convey obligation or advisability or desirability? 

In either case "devrais" would be appropriate, but if we want to express "You should have been a teacher" for example then "Tu aurais dû être professeur" also could be thought of as conveying obligation or advisability or desirability.

So perhaps it is a matter of style as to whether devoir or avoir is used in the conditional in the above context.

This where Cécile's input would be welcome for an expert opinion.

Jim

Jim, I am having trouble following this now. I think the discussion has moved from differences in meaning between tenses, to how to formulate different statements ?

I am pretty certain that  “Devrais avoir dû “ is not grammatically correct though, and that some of the verb constructions the translators give for complex conditional/tense combinations are not always grammatically correct either.