Yesterday I got this note from a reader:
I seem to remember a Language Log post about the construction "I appreciate you coming over to help me" as opposed to the prescriptively approved "I appreciate your coming over to help me." I am in a discussion with a prescriptivist about the validity of the former but I can't find the relevant post on LL. Can you help?
There have been a couple of relevant posts over the years, but what this reader really needed was a reminder to check his copy of the Merriam-Webster's Dictionary of English Usage (or the concise edition of the same work).
Here's the MWDEU entry on possessive with gerund:
(Click on the page image below for a larger version…)
If you don't already own it, you should go buy this book. And just as important, when a question of English usage comes up, it's one of the first places that you should look for an evidence-based opinion.
For a deeper discussion of the grammar of these contructions, see CGEL 14 § 1.5 (pp. 1187-1193), "The structure of gerund-participials", which implicitly amends MWDEU's generalization that "From the middle of the 18th century to the present time, grammarians […] cannot parse it, they cannot explain it, they cannot decide whether the possessive is correct or not". CGEL will also give you another argument against the quaint view that the possessive should always be obligatory, namely the treatment of fused-head demonstratives like this and that:
I object to this being called a loophole.
*I object to this's being called a loophole.
Some customers skipped out on their drink orders, despite that being all they had to pay for.
*?Some customers skipped out on their drink orders, despite that's being all they had to pay for.
For a more quantitative picture of current informal usage — and some mysteries about differences among pronouns in particular contexts — you could collect some (alas mostly bogus) web counts. Compare
|appreciate me helping||211||appreciate my helping||102||2.1 to 1|
|appreciate you helping||6,330||appreciate your helping||16,500||1 to 2.6|
|appreciate him helping||544||appreciate his helping||250||2.2 to 1|
|appreciate us helping||118||appreciate our helping||14,900||1 to 126|
|appreciate them helping||698||appreciate their helping||425||1.6 to 1|
|prevent me leaving||878||prevent my leaving||3,880||1 to 4.4|
|prevent you leaving||4,450||prevent your leaving||1,160||3.8 to 1|
|prevent him leaving||3,130||prevent his leaving||12,900||1 to 4.12|
|prevent us leaving||627||prevent our leaving||2,530||1 to 4.0|
|prevent them leaving||630||prevent their leaving||4,300||1 to 6.8|
But for a practical overview of opinion and evidence, it's hard to beat MW(C)DEU. It's the prescriptivist's description (James Kilpatrick blurbed it as "A writer's best friend" on the cover of the Concise edition) and the descriptivist's prescription (that hard set at Language Log have often recommended it).