Sure, I can help you convert those verbs into the present simple tense. Here are the sentences with the verbs in the correct form:

1. They **go** on holiday every winter.
2. The days **are** longer in summer.
3. She often **talks** to herself.
4. Oak trees **grow** very slowly.
5. My dog **does not (doesn't) eat** vegetables.
6. My brother **does not (doesn't) like** animals.
7. Most people **do not (don't) like** to visit a doctor.
8. Do you **live** in the country or in the city?
9. What do you often **do** in the evenings?
10. My sister never **goes** out in the evening.
11. He usually **works** with paints and brushes.
12. Do you know anyone who **speaks** Chinese?
13. I **am not** a student. I **am** a teacher. She **is** a teacher too.