Sleep in 睡懒觉 如：I love to sleep in on Sundays! It helps me catch up on my sleep.
注意：sleep in 指 「有意的、專門多睡一會兒」，而不是不小心起晚了、睡過頭了。
have a lie-in 睡懒觉
如：Since the athlete's training had been cancelled, she decided to have a lie-in. She slept in for an extra two hours!
如果想表達 「睡過了」，那麼應該用動詞 oversleep。
如：I always oversleep on a Monday.
sleep over 去別人家借宿、在別人家裡過夜
如：It was so nice to see my high school best friend again! We talked until late and I decided to sleep over rather than drive home in the dark.
另外，在不少西方國家，孩子們通常會在參加慶祝生日聚會等特殊的場合到另一個小朋友的家裡去，然後在那位小朋友的家裡留宿過夜。我們把這個活動叫做 「having a sleepover party」。
For my birthday, I think I want to have a big sleepover! We can eat ice cream and watch movies!
turn in 表示 「上床睡覺」 這個動作
Is that the time? It's late! I think I'll turn in. Goodnight!
You look exhausted! What time did you turn in last night?
