nebukuro de neru.

I sleep in a sleeping bag.

Breakdown of nebukuro de neru.

• で: means particle
• 寝ねる: to sleep
• 寝袋ねぶくろ: a sleeping bag

Questions & Answers about nebukuro de neru.

Why is the particle で used in 寝袋で寝る?

Here, で marks the place or means in which the action happens.

So 寝袋で寝る means something like sleep in a sleeping bag.

In Japanese, で is often used for:

• the place where an action happens
  
  • 公園で遊ぶ = play in the park
• the means/tool used to do something
  
  • バスで行く = go by bus

In this sentence, 寝袋 is treated as the place/context in which you sleep, so で is natural.

Why not use に instead of で?

That is a very common question, because English in can correspond to either で or に depending on the situation.

• で focuses on where the action happens
• に often marks destination, existence, or a point of result

So:

• 寝袋で寝る = sleep in a sleeping bag
  This is the standard simple sentence.
• 寝袋に入る = get into a sleeping bag
  Here に marks where you enter/go into.

If you want to express both ideas, you could say:

• 寝袋に入って寝る = get into a sleeping bag and sleep

So に is not impossible in related sentences, but in 寝る, the natural particle for the place of the action is usually で.

What is the role of each part in 寝袋で寝る?