Tengo que hacer la tarea.
English: I have to do the homework.
In Spanish, 'expresiones de obligación' are ways to say that someone must or has to do something. These expressions show necessity or obligation.
Use these forms when you want to say that someone needs to do something, when giving advice, or when talking about general rules or responsibilities.
Tengo que hacer la tarea.
English: I have to do the homework.
Debes beber más agua.
English: You should drink more water.
Hay que respetar las reglas.
English: One must respect the rules.
Tenemos que llegar temprano.
English: We have to arrive early.
Debo llamar a mi madre.
English: I must call my mother.