Some great sites there, Father Steve.
The history of the phrasal verb, as I see it, is rooted in the Germanic languages. There is a concept in modern German that they refer to as separable prefixes; beligerentyouth could probably supply better information than I could about separable prefixes in German, but suffice it to say that the prefixes in question are, in general, indistinguishable from prepositions. They can also be placed at the end of a sentence in some constructions of the normal German sentence. Father Steve's third link above is a very good description of phrasal verbs and I won't go into that here. I will add that traditional grammarians seem to have lost the concept of phrasal verbs and it is not something that is taught in English as a First Language classes. I'm glad to see that it is a concept taught in ESL. But back to the history. The concept is recognized in most Germanic languages that I know anything much about but in English it has given rise to the complaints about ending sentences with prepositions. Since they don't teach it in EFL classes, the difference between a preposition and the separable prefix has become glossed over and folks who are trying too hard to be correct will often come up with extremely contorted sentences. Winston Churchill's famous "It is a silly rule up with which I shall not put" is, of course, a humorous (or should I say humourous) riposte.
The idea of BASIC English, a subset of the language consisting of just several thousand words, relies heavily on the phrasal verb which prevents it from being one of the things it was supposed to be which is an easy road to English for foreign language speakers.
Was that confusing enough? If not I can try again.
