Juan y alberto en mi casa frecuentemente. estudia estudiaban estudiabas estudió

The right conjugation of the verb "estudiar" is:

- Juan y Alberto estudiaban en mi casa frecuentemente.

Explanation:

The translation of the sentence is:

- Juan and Alberto studied in my house frequently.

The verb "estudiar" in the Imperfect Past of the Indicative Form has the conjugations shown below, taking into account personal pronouns:

Juan and Alberto is a noun that can be replaced by the personal pronoun "ellos", whereby the correct conjugation of the verb in the mentioned time is "estudiaban". The option "estudia" belongs to the third person of the Simple Present Tense (él, ella, ello) and the option "estudió" belongs to the third person as well but of the Simple Past, so none of these applied either.