Breakdown of Мой брат едет на море на поезде.
брат
brother
море
sea
мой
my (мой, моя, моё) / mine
на
on, at / by (transport) / to (a place) / to (in answer to)
Questions & Answers about Мой брат едет на море на поезде.
Why does this sentence use едет instead of идёт for 'is going'?
Едет comes from the verb ехать, which means to go by a vehicle or transport. Since the brother is taking a train, we must use едет. If he were walking, we would use идёт.
Why is the word на used twice here?
In Russian, на is a very versatile preposition and it does two different jobs in this sentence. The first на in на море indicates the destination (to the sea). The second на in на поезде indicates the method of transportation (by train).
Why do we say на море instead of в море for 'to the sea'?
Going on a beach holiday or to the seaside traditionally takes на. If you used в and said в море, it would mean going literally into the water, as if the train were driving into the ocean!
Does the word море change its ending here to show it is the destination?
It is in the Accusative case because it is the destination of a motion, but the spelling does not change. Море is a neuter noun, and inanimate neuter nouns look exactly the same in the Accusative case as they do in their basic dictionary form.