Questions & Answers about Я уверен в своём наставнике.
Why does "уверен" take the preposition "в" + Prepositional case here?
In Russian, the short adjective уверен (sure/confident) is heavily tied to the preposition в followed by the Prepositional case. While in English we might say "sure of" or "confident about," Russian literally says "confident in" (уверен в).
Could I say "в моём наставнике" instead of "в своём"?
Grammatically, yes, but Russian strongly prefers the reflexive possessive свой (here as своём) when the "owner" is the subject of the sentence. Since the subject is Я, своём naturally reflects back to mean "my own". Using моём here sounds a bit clunky to native ears, though it would be completely understood.
Why use the short form "уверен" instead of the full adjective "уверенный"?
When an adjective acts as the main state or predicate of a sentence (like saying "I am confident" rather than "a confident person"), Russian typically uses the short form. You would use the full form уверенный to describe a noun directly, such as уверенный наставник (a confident mentor).
How could I use this lesson's grammar to say "I am confident in him AS a mentor"?