I BELIEVE YOU WOULD SAY, EL CHICOS NECESITAN ESTUDIAR. BUT IM NOT 100% SURE. HOPE THIS HELPS!
In Spanish, two boys would say "necesitamos" to express "we need." The verb "necesitar" (to need) is conjugated in the first-person plural form, which remains the same regardless of gender. Thus, both boys would use "necesitamos" to convey their need.
You say, "gemelos."
"Estudiar"
You can say los chicos for the boys, and las chicas for the girls.
English: "study hall" Spanish: "hora de estudio"
they study→ ellos/ellas estudian
Nothing, that's in English. But if you meant to say HOW to say teenage boys, then its "adolescentes"
"You all don't study" in Spanish is "Usted no todos estudian."
hola chicos
"To study" is "estudiar" in Spanish. In speaking af a room, "despacho" or "estudio". A study is "un estudio".
Voy a estudiar.
Estudiar