Quote Originally Posted by Timon View Post
Is it not the subkunctive? Here is what Grammar In Use (Cambridge) says: "We can sometimes report advice, orders, requests, suggestions, etc. about things that need to be done or are desirable using a that-dause with should + bare infinitive. In formal contexts, particularly in written English, we can often leave out should but keep the infinitive. An infinitive used in this way is sometimes called the subjunctive.".

My sentence was: "My first assumption was also that "to file suit" be a phrasal verb.". Does this sentence not comply with the rule above?
I believe it does not and you were right. But I do not see why I was wrong. It is kind of a gap in my understanding.
The crucial bit is "things that need to be done or are desirable". Neither does the phrase "to file suit" need to be made a phrasal verb, nor is it desirable for it to become one. It either is one or it is not. The subjunctive has a function similar to the Russian particle бы. Imagine you would say (translation is hopeless here, but I guess you get the idea): "to file suit" было бы "phrasal verb". I think that doesn't make much sense, does it?

If you use subjunctive, then you say something to the effect "I wish that from now on "to file suit" (should) be considered as a phrasal verb". That's quite different from a simple "it is a phrasal verb".