Использование rather:

1. We often use rather for negative ideas.

Example: The weather isn't so good. It's rather cloudy.

2. When we use rather for positive ideas, it means "unusually" or "surprisingly".

Example: These oranges are rather good. Where did you buy them?

3. used for correcting what you have just said

Example: He couldn't help us, or rather he didn't want to.

4. used as a predeterminer (followed by 'a')

Example: This is rather a good wine.

5. can be used before a verb

Example: He rather enjoys telling other people what to do.

rather than - used for saying that one thing is preferred to another or happens instead of another.

Example: We want the matter settled sooner rather than later.

Примечание:

predeterminer - a word that can come before a determiner (=a word such as 'a', 'the', 'his', or 'this'), and gives more information about a noun.
In the phrases 'all my fingers' and 'half a loaf', the words 'all' and 'half' are predeterminers.