Did you know there are 2 type of sleep in Japanese words?
For sleeping as in “go to bed/lying down to take a nap”, it is 寝る (Neru). And the opposite is 起きる (Okiru), which means to get up from the lie down posture).
For sleeping as in “you’re in train/classroom and fell asleep” (not necessarily lying down), it is 眠る (Nemuru). So to wake up someone who’s sleeping on a train, you will need to use 目覚める (Mezameru), which means to open their eyes and be sober.
The key here is in the posture! 😀 But sometimes they are also interchangeable. One thing to note though, when you’re talking about “What time do you go to sleep at night?” or anything similar, you always use 寝る (Neru).
Happy Learning ｡ﾟ✶ฺ.ヽ(*´∀`*)ﾉ.✶ฺﾟ｡