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"Tener que" is a transitive verb phrase which is often translated as "to have to", and "deber de" is an auxiliary verb which is often translated as "must". Learn more about the difference between "tener que" and "deber de" below.
tener que(
teh
-
nehr
keh
)A transitive verb phrase is a phrase that combines a verb with a preposition or other particle and requires a direct object (e.g., take out the trash.).
1. (general)
a. to have to
Tengo que sacar la basura, apesta.I have to take the trash out; it stinks.
Los participantes tienen que llenar el formulario de salud.The participants have to fill out the health form.
b. to have got to
Tienes que decírselo. Solo complicará las cosas si no lo haces.You've got to tell her. It will only complicate things if you don't.
deber de(
deh
-
behr
deh
)An auxiliary verb, or helper verb, is a conjugated verb that comes before a main verb and determines the main verb's tense, mood, or aspect (e.g., I have gone.).
a. must
Debe de ser muy interesante poder viajar a las islas Galápagos.It must be really interesting to be able to travel to the Galapagos Islands.
2. (colloquial) (used with an infinitive to express obligation)
A word or phrase that is commonly used in conversational speech (e.g., skinny, grandma).
a. have to
Esto es chantaje, Juan. Debes de decírselo a la policía.This is blackmail, Juan. You have to tell the police.
A phrase is a group of words commonly used together (e.g., once upon a time).
a. duty to
Tengo el deber de comunicarle que su presencia en nuestro país no es bien recibida.It is my duty to inform you that your presence in our country is not welcome.
b. obligation as
Mi deber de ciudadano es denunciar este delito ambiental a las autoridades.My obligation as a citizen is to report this environmental crime to the authorities.