I just finished a lesson this morning with my French students on using the imperative with various pronouns. I was refining their knowledge of the imperative (I thought) by adding some pronouns and going over their order within affirmative commands. I explained that the pronouns "me" and "te" change to "moi" and "toi" (as in "Aide-moi!" and "Lève-toi!").
I then explained that there was, of course, an exception: If the "moi" and "toi" are followed by the pronoun "y" or "en," the "moi" and "toi" contract to "m'" and "t'," respectively, as in "Va-t'en!" and "Faites-m'y penser."
Now, I have a native French speaker from Cameroon in my class, and he told me that "Faites-m'y penser" is incorrect and that it is "Faites-moi y penser" instead.