The Japanese particle で is one of the first particles that is typically taught, because it’s usage to mean where an action takes place, or “by means of” is pretty easy to understand. Here is one example of each:
- 僕は部屋でテレビを見た。
- I watched TV in the room.
- 僕たち、バスで海に行った。
- We went to the beach via bus.
One meaning that is a bit more advanced is when で is used to explain the reason for something. This is may be a bit tricky to use for beginners at first, but once you grasp it you’ll be using it no time.
- 女の子が病気で倒れた。
- The girl collapsed due to an illness.
- 彼はショックで口がきけなくなっちゃった。
- He fell silent (unable to speak) out of shock.
- 昨日、不安で眠れなかった。
- Yesterday, I was so anxious I couldn’t sleep.
It’s important to understand that で doesn’t literally mean “because of”, rather it is closer to just “and”, and can be seen as a shortened form of ”であって”. So the last sentence above is literally “Yesterday I was anxious and couldn’t sleep”. However, when things are connected via で (or a verb in the “te” form like して) there can be an implied causation.
If you wanted to rewrite the last sentence using an explicit “because”, you would end up with this:
- 昨日、不安だったから眠れなかった。
While this is technically correct, it sounds unnatural to me and the original one (using で) sounds much better.
Another interesting fact is that the word “ので”, when used to mean “because”, is really just の being used to change the prior verb into a noun, and で to connect this to the following sentence in the sense of “and”. Or at least that is my interpretation of it (:
One final note: strictly speaking, in some of the above usages for で one could argue that rather than the particle ”で”, the “te” form of the copula (”だ”, meaning “is”) is being used. I’m not sure which is correct, but ultimately how you categorize the grammar isn’t too important, as long as you understand the meaning and how to use it.