I feel when we use "comma + which", the clause right before "comma" can act as a subject or object of the clause after "which". so I made 5 sentences to make sure I understand right.
- I get up late, which I feel I have to fix.
I get up late is a object of "fix".
- I eat a fruit every morning, which I think is really great for my health.
I eat a fruit every morning is a subject of "is".
- I drink a cup of coffee once I finish eating lunch, which I think makes me more productive.
I drink a cup of coffee once I finish eating lunch is a subject of "makes".
- My girlfriend is a vegetarian, which is what I like about her.
My girlfriend is a vegetarian is a subject of "is".
- My girlfriend is a vegetarian, which I like about my girlfriend.
My girlfriend is a vegetarian is an object of "like".
Am I right to think this way?