Answer:
1. He/she (or name) likes to eat oatmeal and waffles for dinner sometimes.
2. No change.
3. They carried the bags, so I held the door for them.
4. No change
5. We go (replaceable with any subject/infinitive) to school in the morning when the sun comes up.
6. Dad was driving the car and I fell asleep in the backseat.
Explanation:
1. It was missing a subject to go along with, and hadn't made sense left like that without a subject.
3. A conjunction was needed for the 2 causes to be conjoined together, like so.
5. It was missing a subject and infinitive to make sense
6. Needed a conjunction like and to be correct.