Hi, I have to take an english exam and I have an exercice in wich I'm asked to "identify the following constructions".

For example:

* She - might have missed - the train
* We - needn't have translated - the passage

What does my teacher wants to know ? If it's a complexe or simple sentence ? I have no idea. :/
AnonymousI'm asked to "identify the following constructions" ...What does my teacher wants want to know?
It's not possible to answer with any certainty without knowing which constructions you have been discussing in your course at this point in your studies. There are subjects there, and modal verbs, and auxiliary verbs, and pronouns, and nouns, and objects. Who knows?

CJ is right: there is no way for us to know. But if your teacher has divided the sentences like that, then it is more likely that s/he just wants you to identify these:

She (SUBJECT) - might have missed (VERB) - the train (OBJECT)