In a complex sentence, what does the second part of the sentence refer to?

Question

Taking a sentence for example:

普段はスプーンで食べるがないから箸で - I normally use spoon to eat but because there is no (spoon), I use chopsticks

I made that sentence up so it might be wrong

In the sentence above, what is the ない referring to?Is it referring to the スプーン(marked by で particle) or is it referring to the 食べる(verb), or is it referring to the 普段 (marked by the は) particle.

Also, for the second part of the sentence, I am assuming the 箸で refers to the verb that comes before the second part of the sentence. In this case, the 食べる. Is this correct? Are there any general "rules" in a complex sentence as to what the second part of the sentence refers to?

Answer 1

I started writing a comment responding to your last comment and then realized I was writing an answer, so I am just going to write an answer. Putting aside questions about what the most natural way to say this would be, for your given sentence

普段はスプーンで食べるがないから箸で

The only reasonable interpretation here that the subject of the verb ない is スプーン.

In the comments, you clarified that what you really want to know is something to the effect of

Are there rules for disambiguating subject/object omission across multiple clauses?

Unfortunately, the answer to this is largely just no. Most speakers work out the content of these omissions based on what makes the most sense, and there are certainly no hard rules that you could apply based on things like particle choice or simple surface level linguistic information. Also, this process is largely the same regardless of the number of clauses in the sentence.

Here is a (somewhat contrived) example:

私は車で行くつもりだったけど、壊れたから電車で行った

I was planning to go by car, but (my car) broke so I went by train

私は車で行くつもりだったけど、鍵をなくしたから電車で行った

I was planning to go by car, but (I) lost (my) keys so I went by train

As you can see, the subject of 壊れた is presumed to be the car while the subject of 鍵をなくした is presumed to be the speaker. Unfortunately, judgements like this are made using world knowledge ("common sense") and there typically aren't grammatical markers you can count on. This, incidentally, is one of the main reasons why so many machine translation systems struggle with Japanese.

The fact that in this case the transitivity of the verbs is different is just coincidental; the reason in second sentence could also be something like 酔ったから.

Edit: some related posts can be found here, here here and here. There are probably more; this is a fairly common topic.