Translation:My brother plays on a soccer team.
Just a note. If the student here is not American (.e.g. British), they would say football, not soccer. As far as I know, the US is the only country in the world that says soccer for the game everyone else calls football. BTW, I believe the expression "American Football" is what the Brits use for what Americans call football.
"As far as I know, the US is the only country in the world that says soccer " Not that it is normal for all, but on both British and Australian shows, they do say Soccer from time to time. I believe I have also seen a show in New Zealand where they called it soccer as well.
A lot of non-native English speakers here are writing things that are simply wrong. The translation above, "My brother plays on a soccer team", is American English and would NEVER be used by a native English speaker.
Firstly, the word 'soccer' is almost never used. In my 50 years as a fan I don't think I have ever heard it called soccer.
Secondly, nobody plays 'on' a team. The most common way to say it would be 'for' a team, although under certain circumstances people sometimes say 'in' a team.
No full-form adjective looks like that (check the endings ). Basically, all Russian adjectival endings are at least two letters long and always start with a vowel.
The major exception is how "animal-possessives" and the word for "third" behave. They have a /j/-sound after a soft consonant almost everywhere in their endings: третий→третья,третье, третьи, третьего, третью... Normal adjectives have two vowels instead of ь + vowel and just -его, -им instead of -ьего, -ьим.
Anyway... to have a neuter SHORT-form adjective as a predicate here, you would have to actually have the predicate consist of "to be" with an adjective. In reality, "plays" is the verb that acts as a predicate in the sentence.