Here are the two phrases I used most during my first few days in Morocco:
*'La, rrhali buzzef, a sidi' : 'No, that is very expensive, sir.'
Every time I used this phrase in the souks (marketplace) the merchants responded with laughter and an immediate reduction in price. Even when the price of certain wares were absurdly cheap, I'd reflexively complain about the expense. We spent our first few days wandering the famous souks of Marrakesh and I had every opportunity to practice my Arabic as I haggled for everything from glasses of fresh orange juice to matching gold shoes for my girls.
(The smiling man in the tan jacket is my wonderful father-in-law)
The second, and even more important phrase, is:
*'Lekhlif' : direct translation 'may the Lord return it back to you.'
Use: uttering this phrase is your only hope of getting Moroccans to stop feeding you. If you simply say, 'shabet' (I'm full) they will assume you are just being shy, and will reward your graciousness with even more food. I didn't learn this phrase until I had spent two gastronomically agonizing months in Morocco. I'm passing this on so no one else will suffer a similar fate. Just trust me and say 'lekhilf' at your first hint of feeling full.
The picture below is of Jmal F'na at night. That night we ate at one of the outdoor stalls under the stars and I forced myself to ignore how full I became as plate after plate of marvelous food was put before me: warm bread, perfectly seasoned chicken kebabs, fried eggplant, salty black olives, platters of small fried fish, all washed down with coke straight from glass bottles.