睡觉 =睡v.+觉n. 例句：太晚了，你该去睡(觉)了。 睡一会儿（觉） 睡几分钟（觉） 相似的：喝茶=喝v+茶n 喝一杯茶 喝几口茶 喝一会儿茶 睡+觉，是唯一的，听的人可以明白，所以“觉”可以省略 喝+水/酒/茶…，不唯一，听的人不明白，所以“茶”不可以省略

I never thought in this way, but I think it makes sense. Let’s try it: Donald: ‘What did you do?’ Joe: ‘I slept (a sleep).’ 睡（了一个）觉 Donald: ‘How was your sleep?’ 觉 Joe: ‘I slept well.’ 睡（得好） Donald: ‘How long did you sleep?’ 睡（了多久） Joe: ‘I slept for an hour.’ 睡（了） Donald: ‘ok sleepy Joe. Go back to sleep (a sleep).’ (回去)睡觉 The explanation works!

Verb ‘to sleep’ with objects is used very rarely in spoken English, e.g.: He slept the sleep of innocent. Use of verb ‘to sleep’ without object is very straightforward, e.g.: I slept well. A ‘sleep’ as a noun: e.g.: A brief sleep.