This is the 39th most frequent Russian word.
а
The Russian word "а" means "and," "but," or "whereas," depending on the context.
This use of 'а' implies a contrast or an opposite outcome between the two clauses.
Я хотел пойти гулять, а пошёл на работу.
I wanted to go for a walk, but instead, I went to work.
Here, 'а' connects two clauses, highlighting a simultaneous or correlational relationship between them.
Я думал, а он уже знал ответ.
I was thinking, while he already knew the answer.
In this sentence, 'а' is used to indicate a comparison or distinction between what the two subjects are doing.