Questions & Answers about Кіт нявкає, а собака гавкає і кусає.
In this sentence, а connects two clauses and shows a contrast:
- Кіт нявкає — the cat meows
- а собака гавкає і кусає — while/but the dog barks and bites
So а often means something like and, while, or but, depending on context. Here it feels like while/as for or a mild but: the cat does one thing, and the dog does something different.
If you used і instead, it would sound more like simple addition, with less contrast.
Because а is joining two separate clauses, each with its own subject and verb:
- Кіт нявкає
- собака гавкає і кусає
In Ukrainian, when coordinating clauses like this, a comma before а is normal.