Alejandro estudia para el examen.
The correct answer is the second one.
Spanish verbs have suffixes for each of the pronouns, just like English does (only for the third person singular). So, this is how you conjugate the verb estudiar in Spanish:
1. yo estudio 1. nosotros estudiamos
2. tu estudias 2. vosotros <span>estudiáis
3. el/ella/Usted estudia 3. Ellos/ellas/Ustedes estudian</span>
1.tengo
2.sere
3.hablará
4.fueras o serás (not to sure for this one)
5. Puedo
6. Estudiábamos
7. Trabajas
8. Supiera
9. Tuviéramos
10. Fuera
Answer: These are the correct answers:
1. por
2. por
3. para
4. para
5. para
6. por
Explanation: Just to elaborate a little on the answer, it can also be added that in this exercise they are asking you to choose the most appropriate preposition. "Por" can be translated as by, among other meanings, and "para" can be translated as for, among other meanings as well. So, for instance, in sentence 6, the speaker is saying: "My cousin was raised BY my parents." And in sentence 3, the speaker is saying "I bought some flowers FOR Ana."