Okay, this is the area of linguistics that I'm really interested in without having any special expertise. So, captive audience, pay heed!
English, to me, is a
forward looking and indicative language. We have lots of ways of making the present and the future work well and easily, more than most languages. We seem to have about the same number of past tense formations as most other European languages. Please bear with me, I haven't much time, certainly not enough to give examples of what I mean by that last statement.
We handle the future with aplomb. Look at the awkwardness of German's future tense formation, and Latinate languages generally only have one approach to future sentence and verb formation. Yes, there are exceptions, but not as many as in English. We can muck around in the future with a will.
But English does handle some things very awkwardly and the double genitive issue discussed in this thread is one of them. If we had case agreement, I guess it would be easier. As someone (NickW? tsuwm?) has pointed out, the use of the possessive apostrophe is uncertain and failing To say the formation "a friend of Molly's" is correct based on its existence and usage since the 14th century is actually begging the question. Technically, "a friend of Molly" must be correct, because the double genitive formation is logically wrong, even though it has an honoured history and is seen as grammatically correct. Not trying to buy a fight here, just pointing it out.
But we put up with this stuff because of the other freedoms that English sentence formation allows us. The orient/orientate argument could hardly exist in many other languages because of their more rigid syntactic structures.
But, hey, it's what makes English such an interesting critter!
