do I use は or が?

I tried translating “electricity generates heat” and it said “電気が熱を発生させる” but shouldn’t it be “は” instead of “が”? I want to know which particle to use when stating a fact or just talking about something in general.

4 comments
  1. Ah the eternal quandary of the Japanese student. I’m by no means fluent myself but it’s my understanding that most of the time you can use either and be understood. I was told that college level students write dissertation papers on は vs が. It’s hard to find a definitive answer. Like most things in japanese it boils down to, “you just have to know”

    頑張ってね I know your frustration well.

  2. use は, it’s not always the case and by no means it’s the best explanation but I use this kind of logic:
    は=> accent on the action
    accent on the subject <=が
    電気は**熱を発生させる** electricity **generates heat**
    **電気**が熱を発生させる heat is generated by **electricity**

  3. In this case, は is more general and talks about electricity as a whole.

    が here would make it so that you’re speaking about this specific mechanism or device that you’re showing. Depending on the context it can also be emphasis. “ELECTRICITY is what’s generating heat.”

  4. [Caveat: This is generalized stuff, there are many additional nuances and edge cases that I haven’t mentioned].

    Think of Japanese sentences (phrases) having a ‘topic->comment’ structure. Also they are further qualified by the existing ‘context’. What does this all mean?

    * **Context** – Everything that’s already relevant to what is currently being said. This includes not only what has already been said, but (maybe) the current surroundings, people’s expressions, gesticulations, non verbal sounds… etc. Context continues to build and change during a conversation as new information gathers. Basically this is true for any language.
    * **Topic** – This is a verbal part of the context. It describes what the conversation is currently about in terms of concepts all parties already know (because it has already been said – e.g. “*You know John, well…*”) or should already implicitly understand (e.g. “*The weather today…*”). The key point is that the topic is not (or shouldn’t be) new or surprising information to anyone. All languages track topics somehow, and Japanese does so using the **は** particle.
    * **Comment** – This is the new stuff that you are saying. It consists of a subject (marked with **が** in Japanese, but often omitted when it is obvious from context or the same as the topic), and a predicate (e.g. “[*The sky*] (subject) [*has turned green*!] (predicate)”).

    Because **は** marks the topic, and the topic is already known/understood information, attention is shifted to the new stuff being said (the comment) – hence は ‘throws’ the emphasis forward to what follows it (as we are generally more interested in new information). This is especially true when the topic and subject are the same.

    As for **が**, it marks the subject and, when specified, it often emphasizes the subject because it is new information (NB. The subject can be new information, but doesn’t always have to be – just so long as the subject-predicate pair combine to give new information). Hence が can be used to ‘throw’ emphasis back onto the subject it marks.

    So – if you are talking generally about something then you would tend to use は to indicate the thing you are talking about (unless the thing is new info – then you need が). If you specifically want to emphasize the thing itself, then you might choose が instead.

    In your example you say (in broken English) “*Electricity* (が) *causes the doing of generating heat*”. As we all know what electricity is you could have used は, but then it would have just been a throwaway statement. Choosing が emphasizes that it’s ‘electricity’ that causes heat to be generated.

    For more info, I found [this link](https://8020japanese.com/wa-vs-ga/) to be quite helpful.

Leave a Reply
You May Also Like