why does my car shake when in drive but not in motion? at a stop it will shake- on 2003 Oldsmobile Alero

until i take off. what causes this to happen?

Have compression checked, and for vacuum leak(s)! Low compression, or misfire, on one or more cylinders can cause this, a vacuum leak also!
It is still there when driving down the road, just not as pronounced.
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Also , just a thought......maybe bad engine mount(s)?