I've a stomachache. (stomachache是一个词)
Are you asleep?(asleep是形容词,sleep是动词,一个句子不可能出现are,sleep两个动词)
我肚子疼:I've a stomach ache.
你睡了吗: Are you asleep?
我肚子疼:My stomach hurts.
你睡了吗: Did you sleep yet?
I've got a stomachache.
Are you going to sleep yet?/Are you going to bed yet?
I have a stomachache.
Are you sleep?