For simple statements:
* Avoir dû (most common) - This is the most direct translation of "should have," used for simple statements about past obligations or recommendations.
* Example: "I should have studied more." - J'aurais dû étudier plus.
For regrets and missed opportunities:
* Avoir pu - This translates to "should have been able to" and expresses regret for a missed opportunity.
* Example: "I should have gone to the party." - J'aurais pu aller à la fête.
* Avoir su - This translates to "if only I had known," implying that a different decision would have been made with prior knowledge.
* Example: "I should have known better." - J'aurais su.
For advice or criticism:
* Avoir fait - This means "should have done" and is used to offer advice or critique of past actions.
* Example: "You should have told her the truth." - Tu aurais dû lui dire la vérité.
For strong obligation or necessity:
* Devoir - This translates to "have to" and can be used to express a stronger obligation or necessity in the past.
* Example: "I should have been there." - J'aurais dû être là.
For expressing disappointment:
* Il aurait fallu - This translates to "it would have been necessary" and expresses disappointment about a missed opportunity.
* Example: "We should have gone on a vacation." - Il aurait fallu qu'on parte en vacances.
The best translation will depend on the specific context and nuance you want to convey.