Answer:
1. El entrenador ha dado muchas clases de ejercicios aeróbicos antes.
2. Nosotros nunca antes habíamos pasado por esta parte de la ciudad.
3. Quiero conocer a alguien que haya estudiado psicología.
4. En la clase de literatura, ustedes han leído varias novelas interesantes.
5. Mi madre nos ha oído decir antes que queríamos una motocicleta.
6. Necesitas hablar con personas que hayan estado en Cuba.
Explanation:
This sentences are in the tense called in Spanish "pretérito perfecto compuesto". The third and sixth sentences are in the "pretérito perfecto del subjuntivo", this means the action was in the past but it's still linked to the present. In this case they need or want to meet and talk to people who have studied psychology and that have been to Cuba.
The rest of the sentences are in the pretérito perfecto compuesto which is similar to de present perfect in English. It's formed with the verb HABER followed by the verb that denotes the action.
