Greetings all.

I'm fairly new to Russian but feel I am making steady progress.

I sometimes encounter words where one or more letters appear to be unspoken/silent. For example: "следующий" where the "ю" is not spoken and "здравствуйте" where the first "в" is not.

Are there any rules or guidelines for knowing when a word has silent letters, or is it a case-by-case basis that I just have to learn as I encounter them?

Thank you in advance.