So many people have trouble with the little words – especially those which are used in place of the noun (person or thing). Those little words are called PRONOUNS. Perhaps the hardest thing about using them, is that even when the noun is no longer in the sentence, that noun still controls them – for gender, & singular & plural.
More about that here GENDER CONFUSION!
There are various kinds of pronouns – this explains some of them.
For more about using direct & indirect object pronouns, click here IT! ……..PRONOUNS
More about reflexive verbs here DOING IT TO YOURSELF!
Click here for more about Gustar GUSTAR & SIMILAR VERBS
Used without the noun – gender & number specific, controlled by the possession.