Making, letting and getting things done in Spanish
Spanish causation is beautifully simple: hacer + infinitive = to make someone do something. No extra particles.
Esa película me hizo llorar. (That film made me cry.)
El profesor nos hace repetir los verbos. (The teacher makes us repeat the verbs.)
The person affected becomes a pronoun: me hizo llorar, te hará reír, nos hizo esperar.
Dejar + infinitive = to let/allow. Its negative is the everyday way to say "won't let".
Mis padres no me dejan salir entre semana. (My parents don't let me go out on weekdays.)
Déjame pensar un momento. (Let me think for a moment.)
Alternative with the subjunctive: No dejan que salga. Both correct; the infinitive version is lighter.
Mandar + infinitive = to order/have someone do. Pedir que + subjunctive = to ask someone to do.
El médico me mandó descansar. (The doctor told me to rest.)
Le pedí que me ayudara. (I asked him to help me.)
English "ask someone TO do" hides a Spanish subjunctive: pedir que + subjuntivo, never "pedir a alguien a hacer".
English "I had my hair cut" — you didn't cut it yourself. Spanish handles this with cortarse el pelo (context implies the hairdresser) or explicitly with hacerse + infinitive.
Me corté el pelo ayer. (I had my hair cut yesterday — everyone understands the hairdresser did it.)
Se hizo construir una casa en la sierra. (He had a house built in the mountains.)
Don't translate "I had it done" word by word — Spanish either uses the reflexive or hacerse + infinitive.
Dejar moonlights in several meanings — learn the family.
dejar de + inf = to stop: Dejó de fumar.
dejar + object = to leave (something): Dejé las llaves en casa.
dejar prestado = to lend: ¿Me dejas el boli? (everyday "lend")
¿Me dejas...? is how Spaniards actually ask to borrow things — far more common than prestar in speech.
Traps for English speakers
These are the errors English speakers make most often.