Using la/las instead of le, les
Sometimes in Spanish you will hear people incorrectly use the Spanish la/las instead of the correct indirect object pronouns le/les for her. This is called laísmo. For example:
La dije que la quería.
I told her I loved her.
Las ofrecí un café.
I offered them a coffee.
Las pregunté cómo estaban.
I asked them how they were.
These sentences are using la/las as indirect object pronouns referring to her or them (feminine). As indirect object pronouns these should only be le or les (for masculine and feminine.
Laísmo is not as extented as leísmo. It's common to hear this use of la/las in certain parts of Spain, for example in Madrid and in general in the central and central northern part of Spain. Laísmo hardly occurs in Latin America.
Unlike in leísmo, where certain cases are accepted and normalized, laísmo is not accepted, it's considered incorrect.