how to I say 'to work hard' in spanish?
I understand what you're saying, worldwidewil.
You could use the adjective "trabajador(a)" to describe a person as being "hard working".
For example, you could say:
Soy una persona trabajador(a). = I am a hard working person.
(el) Es una persona trabajador. = He is a hard working person.
However, you would have to be careful with this because "trabajador(a)" is also a noun meaning "worker".
I think that you want a word for the adverb "hard" as the word hard modifies the verb to work which is "trabajar".
In my opinion, I think the phrase "to work hard" would be:
trabajar duro = to work hard
The translation feature of this Web site doesn't always give a correct response because it's using 3 different machine translations.
Use the site's translator. You just need the infinitive for "to work" and the adjective for "hard." Also if you have time go look at the Spanish lessons on the site in the top left hand corner under "Learn Spanish." If you go there you'll find these kinds of questions easily answerable on your own after a very short period of study.
I just get the feeling that trabajar duro is a bit spanglish, but you could be right. Trabajador is a word with similar meaning but I don't quite understand how to use it in the sense of 'I work hard'