Answer:
1. Piensas
2. Quiero
3. Duermo
4. Encuentro
5. Empieza
Step-by-step explanation:
In order to solve this problem you have to read and get the context of the sentences, remember that in spanish you use a conjugation of the verb for each of the subjects that you are talking about, so you have to determine the subject and then conjugate the verb, in the first one, is talking to the second person, so Pensar conjugated for the second would be piensas.
2. Is talking in first person, querer is quiero in first person.
3. Is talking in first person, dormir is duermo in first person
4.Is also talking in first person so the verb encontrar in first person would be encuentro.
5. Is talking about the class, that would be third person, the verb empezar would be empieza.