As in English, the "son" in "son chien" works either way: it could be someone else's dog (his/her dog) or it could be his own. Without further context, I'd actually tend to assume that he's helping his own dog (since nobody else has been mentioned), but that distinction won't show up in the translation without adding a level of emphasis that isn't present in the French.
Without context indicating otherwise, french always assumes the possessive is referencing the subject of the sentence. Since English indicates the gender of the possessor rather than the subject, it does not have such a rule. Although many people would still jump to the same conclusion, the English is naturally less definite in this case.
It can mean either "her dog" or "his dog". "Son" is used because "chien" is masculine.
- Il aide sa mère = He's helping his mother. He helps his mother.
- Il aide son père = He's helping his father. He helps his father.
- Il aide sa soeur = He's helping his sister. He helps his sister.
- Il aide son frère = He's helping his brother. He helps his brother.
Grammatically, "son" (and "sa"/"ses") may be translated as either "his" or "her". However in reality, it will be understood as relating to the subject of the sentence. So "il aide son chien" = he helps his dog. If you want to be sure that your talking about "her dog", then you would say "il aide son chien à elle". "Elle aide son chien" = she helps her dog, but "elle aide son chien à lui" = she helps his dog.
"Son" is used specifically because the noun "chien" is masculine. It is interpreted as "his dog" here because that is the way that French speakers would naturally interpret it as referring to the subject of the sentence.
- Il aide son chien = He helps his dog.
- Il aide son chien à elle = He helps her dog.
It is assumed that you know how to conjugate a verb in English. You will need to do the same in French.
- j'aide = I help, I am helping
- tu aides = you help, you are helping ("tu" is the singular, informal "you")
- il/elle aide = he/she helps, he/she is helping
- nous aidons = we help, we are helping
- vous aidez = you help, you are helping ("vous" may be singular polite or plural "you")
- ils/elles aident = they help, they are helping
Yet another multiple choice question without the correct word offered as one of the possible correct answers. 'Aide' was left out of the question but was not one of the available choices. How am I supposed to get this right? PLEASE CHECK YOUR MULTIPLE CHOICE QUESTIONS, DUOLINGO! I am using an iPad.