phrasal verbs

I know that in some phrasal verbs (such as ‘get over’) the pronoun can’t be placed between the verb and the preposition ( as in ‘get it over’),therefore it would only be correct ‘get over it’. Are there any other verbs that use this pattern? I know that it’s some kind of exception, but how can I know when it’s wrong to place the pronoun between the verb and the preposition?

When you “get over it” (in the sense of overcoming or recovering from something) you are not “getting it” in some way that is “over”, you are “getting” into a situation where you are “over it”. In other words, “it” is logically the object of the preposition “over”, not of the verb “get”. Therefore “get it over” cannot make sense with this meaning. There are lots of similar examples – “pick on”, “look into”, “come across”, etc. – where the object cannot come directly after the verb because it is not logically the object of the verb.

In fact, “get it over” is also possible, but it has the completely different meaning of dealing with or undergoing something that is unpleasant but has to be faced. In this case “it” is the object of “get”.

Could ‘get it over’ mean something like ‘finish it/complete it’?

The key sense is that you don’t want to do/undergo something, but you must, so you might as well do/undergo it now. It would not be used merely as a synonym for “finish it/complete it”. However, there is also the consequence that once you’ve “got it over” it will be finished/completed, and so you won’t have to worry about it any more.