In Spanish you can use 2 ways to express the same idea when using indirect object pronouns:
"La niña "le" está hablando al hombre" = the girl is talking to/with the man
"La niña está hablándole al hombre" = the girl is talking to/with the man
The Spanish indirect object pronouns are as follows:
1st person me me nos us
2nd person te you os you
3rd person le him, her, you, it les them, you
Like direct object pronouns, Spanish indirect object pronouns are placed in front of the verb.
I'm talking to him. - Le hablo.
He writes to them - Les escribe.
I'm giving the bread to you. - Te doy el pan.
She answered me - Ella me contestó.
Keep in mind:
1.- Literal translations don't always work." Asi es la vida! That's life! (expression)
2.- Most of the times, there's no "why" questions. They're "formulas", "rules" so you'll have to memorize and live with them!
OK, if you're planning to study Spanish linguistics, that's another story!
3.- One comment regarding redundancy, Check them out:
-she doesn't like anything/ She likes nothing.
-We are sad and blue! To avoid cuts and nicks, etc