This is the 7th most frequent Polish word.
a
The Polish word "a" means "and," "but," or "whereas," depending on the context.
In this sentence, 'a' is used as a conjunction indicating a contrast between the preferences of two people.
Ona lubi jabłka, a on woli gruszki.
She likes apples, and he prefers pears.
Here, 'a' serves to contrast two actions, highlighting one that is successfully done versus another that isn't.
Anna szuka książki, a zeszytu nie może znaleźć.
Anna is looking for a book, but cannot find her notebook.
In this case, 'a' introduces a clause that provides reasoning or explanation for the first clause.