turn in

For submitting things, you need a direct object. You turn in *something*. For example, turn in your homework. Or turn in the project proposal. The person you give it to is often implied or mentioned. "Please turn in your exams to the proctor." It’s a clear instruction.

When talking about sleep, it's usually intransitive. You just turn in. You don't turn in *something*. You might say, "I'm exhausted, I think I'll turn in early tonight." Or your mom might say, "It's getting late, time to turn in!" It’s a signal that rest is needed.

• School: A student handing their essay to the teacher. "I need to turn in my history paper by Friday."
• Work: An employee giving a report to their manager. "Make sure you turn in the expense report before the meeting."
• Hotel: A guest returning room keys. "We need to turn in our room keys at checkout."
• Home (Sleep): A parent telling a child it's bedtime. "It's 9 PM, time to turn in!"
• Home (Sleep): An adult feeling tired. "After that long hike, I'm going to turn in right after dinner."

Use the 'submit' meaning for assignments, reports, applications, or anything you're required to hand over. It works in academic and professional settings primarily. Think of official processes.

Use the 'sleep' meaning when you're talking about going to bed for the night. It's generally used in casual conversation. It's a softer way to say 'go to sleep'. It implies you're winding down. Perfect for the end of the day.

Don't use turn in to mean 'give back' something you borrowed. You would return it. For example, you return a library book, you don't turn in a library book.

Don't use it to mean 'deliver' something casually, like giving a gift. You would give or deliver a gift. Turn in has that sense of official handover.

For sleep, avoid it in very formal situations. You wouldn't tell your CEO, "I'm going to turn in now." Stick to 'retire for the night' or 'go to bed'.

Also, don't use it for waking up. It's strictly about going to sleep. No one is turning in at 7 AM!

• ✗ I need to turn in my friend's book. → ✓ I need to return my friend's book.
• ✗ She will turn in the package to the courier. → ✓ She will hand over the package to the courier.
• ✗ Let's turn in for a nap. → ✓ Let's take a nap.
• ✗ He decided to turn in the marathon. → ✓ He decided to complete the marathon.

• Submit: More formal, often used for official documents or applications. "Please submit your application online."
• Hand in: Very similar to turn in for the 'submit' meaning. Often interchangeable. "Hand in your passports at reception."
• Go to bed: Direct and common for the sleep meaning. "It's time for you to go to bed."
• Hit the hay: Very informal slang for going to sleep. "I'm exhausted, I'm gonna hit the hay."

• Turned in: Past tense. "I turned in my essay yesterday."
• Turning in: Present participle. "She's turning in her resignation letter."
• Turn-in: Used as a noun, often for a specific event. "The equipment turn-in is on Thursday."

• What's the difference between turn in and submit?

Submit is often more formal and used for digital or official documents. Turn in is more general for physical items or when speaking casually.

• Can turn in be used for returning borrowed items?

No, you return items. Turn in implies handing something over to an authority or for a specific purpose, not just giving it back.

• Is turn in formal or informal?

It depends on the meaning. 'Submit' is neutral to formal. 'Sleep' is informal to neutral. Context is key!