It depends on the verb. Many people make mistakes on using them. If the verb is direct, use o/a/os/as, if indirect use lhe(s). For a complete explanation, access: http://www.learningportuguese.co.uk/language/object-pronouns.html
Thanks, Paulenrique. This link is to a brilliant website and the explanation about direct and indirect objects is very clear. A
Is this even correct in Brazilian PT? I am a native PT-PT speaker and this is just wrong. Should be "Ela ajuda-os" ou "Ela os ajuda".
Couldn't lhes also replace vocês? Thus, couldn't "Ela lhes ajuda" mean "She helps them" or "She helps you (pl)"?
To be formally correct you have to use "o, a, os, as, lhe, lhes".... man.. and "ajudar" is a bit complicated about using pronouns :( - it depends on the usage to decide which one to use since "lhes" can be used!
You're right. "Lhes" replaces "to them" (a eles) and "to you" (plural) (a vocês).
Anyway, I'm reporting this question because it's grammatically wrong. Some verbs do not admit the pronoun "lhes", such as to assist (assitir) (in the sense of being present), to help (ajudar), to aspire (aspirar), to preside (presidir) and to resort (recorrer), Thus, the right form would be:
Eu ajudarei a você/a eles (not "eu lhes ajudarei"). There are some more rules, but I think it would make it harder for you.
I agree with you. Ajudar takes direct object, the correct is "Ela os ajuda"
But being direct, don't use preposition: "Ela ajuda vocês"
Preposition is used with "ajuda" only when it's a noun, object of another verb:
"Ela envia ajuda a vocês" (She sends help to you)
......but then I went researching, and some say it can take indirect objects as well....damn verb....
honestly if I were to say "I help you(pl)" I would most likely say "Eu vos ajudo". While this may be less gramatically correct, I've heard a bunch of people use te and vos for voce and voces respectively because it's less confusing than using lhe/s or o(s)/a(s).