preocupar

transitive verb

1. to worry (inquietar)

me preocupa no saber nada de él -> I'm worried I haven't heard from him

2. to bother (importar)

sólo le preocupa su apariencia externa -> he's only bothered about his appearance

preocuparse

pronomial verb

1. to worry (inquietarse) (por about), to be worried (por about)

no te preocupes -> don't worry

no te preocupes por ella -> don't worry about her

2. (encargarse)

preocuparse de algo -> to take care of something

preocuparse de hacer algo -> to see to it that something is done

preocuparse de que… -> to make sure that…