Moroccan Arabic

I'm trying to figure out if I've got some basic patterns down, which is just a tad chancy when working from tourist phrasebooks. So to anyone who knows: Am I correct that "I understand" would be "kanfhem," "I understood" would be "fhemt" (much like MSA), "I will understand" is ""ghadi nfhem" (3 consonants in a row? Do I make it like one word?), and the all-important "I don't understand" would be "ma kanfhemsh?"

I guess I'll get it once I'm over there, but I'm sufficiently freaked about Tangier I'd like as many linguistic tools as possible. So thanks if you can help.