1. ¿Sabes hablar inglés?

Must you speak English? 
May you speak English? 
Can you speak English? 
No se

2. Debes hacer tus deberes

You must do your homework 
You can do your homework 
you may do your homework 
No se

3. Debes ayudar a tu madre

You could help your mother 
You must help your mother 
You can help your mother 
No se

4. ¿Puedo llamarte?

May I phone you? 
Must I phone you? 
Should I phone you? 
No se

5. Tengo que aprobar este examen

I have to pass this exam 
I can pass this exam 
I have to pass that exam 
No se