Questions & Answers about Напёрсток защищает палец.
Напёрсток is the subject: it is the thing doing the action.
Палец is the object: it is the thing receiving the action.
So the structure is:
- Напёрсток = thimble
- защищает = protects
- палец = finger
Literally: Thimble protects finger.
In natural English, we say A/The thimble protects a/the finger.
Because it is in the accusative case, and for many inanimate masculine nouns in Russian, the accusative singular looks exactly the same as the nominative singular.
So:
- nominative: палец
- accusative: палец
That is why the direct object still appears as палец.
This is very common in Russian:
- Я вижу стол. = I see the table.
- стол stays стол in the accusative because it is masculine singular and inanimate.