have to + un verbo significa que necesitas hacerlo. Es una norma, o no tienes otra opción.
have to + un verbo
I have to be at school at eight.
We have to wear a uniform at work.
Not "I have be at school at eight." — say "I have to be at school at eight.". Di have to, con to, antes del verbo.
Pruébalo: Amina: Can I leave these boxes in the hall? Lars: No. The landlord checks the halls every week. We ___ keep them in our apartments. Elige lo que dice Lars. (have / have to / don't have to) Respuesta: have to — La dueña revisa los pasillos cada semana, así que dejar las cajas dentro no es opcional: Lars dice have to + keep. A have solo le falta to, y don't have to lo convertiría en algo opcional.
Con he, she, it: has to
Con he, she o it, di has to.
He has to leave at seven.
The doctor has to see ten people today.
Not "He have to leave at seven." — say "He has to leave at seven.". Con he, she o it, di has to.
Pruébalo: Amina: Why is the man in 2B so busy? Lars: He ___ move out on Friday. Elige lo que dice Lars. (have to / has / has to) Respuesta: has to — Con he, di has to + move. have to va con I, you, we y they, y a has solo le falta to.
don't have to + un verbo
don't have to + un verbo significa que no es obligatorio. Puedes hacerlo o no.
You don't have to call me. I'm fine.
We don't have to cook tonight.
Pruébalo: Amina: The library closes at eight. Is my book late? Lars: No. You ___ take it back today. You have two weeks. Elige lo que dice Lars. (don't have to / have to / doesn't have to) Respuesta: don't have to — Amina tiene dos semanas, así que devolver el libro hoy es decisión suya: don't have to + take. have to querría decir que hoy es el último día, y doesn't have to va con he, she o it, no con you.
Con he, she, it: doesn't have to
Con he, she o it, di doesn't have to.
She doesn't have to wear a uniform.
He doesn't have to work on Friday.
Not "She don't have to go." — say "She doesn't have to go.". Con he, she o it, di doesn't have to.
Pruébalo: Amina: Does your friend go to a classroom for her English class? Lars: No. She ___ go. The class is online. Elige lo que dice Lars. (don't have to / doesn't have to / has to) Respuesta: doesn't have to — La clase es online, así que no hace falta ir a un aula, y con she se dice doesn't have to. don't have to va con I, you, we y they, y has to la mandaría al aula.
Preguntar: Do you have to? Does he have to?
Para preguntar por una norma, di Do you have to + un verbo. Con he, she o it, di Does he have to + un verbo.
Do I have to buy a ticket? Yes, you do.
Does she have to study tonight? No, she doesn't.
Not "Does he has to go?" — say "Does he have to go?". Después de does, di have to, no has to.
Pruébalo: Amina: ___ I have to take off my shoes? Lars: Yes, please. The floor is new. Elige la primera palabra de Amina. (Does / Am / Do) Respuesta: Do — Con I, una pregunta sobre una norma empieza con Do: Do I have to take them off? Does va con he, she o it, y Am no va con have to.
Una norma o una elección
¿Necesitas hacerlo? Di have to. ¿Puedes elegir? Di don't have to.
At this school, you have to wear a uniform.
You don't have to wear a tie, but you can.
Pruébalo: Amina: Can I go home now? Lars: Sure. You ___ stay. We can do it tomorrow. Elige lo que dice Lars. (have to / don't have to / has to) Respuesta: don't have to — Pueden hacerlo mañana, así que quedarse es decisión de Amina: don't have to + stay. have to la obligaría a quedarse esta noche, y has to va con he, she o it.