If you are learning indirect-object pronouns, that usually means that you have already had the direct object pronouns. Here's a review: Eng. & Spanish.
INDIRECT OBJECTS DIRECT OBJECTS
me (to, for, at, from me (me)
te (to, for, at, from te (you,fam/sing)
you - fam/sing)
le (to, for, at, from lo (it, him)
him, her, you form) la (it, her)
nos (to, for, at, from nos (us)
os (to, for, at, from os (you = fam/pl)
you = fam/pl)
les (to, for, at, from los (them) masc
them, you-all form)las (them) fem
Now, look closely and you can see that you don't even have to understand the grammar to pick everything except 3rd person singular and plural. THAT is where you must understand that the indirect-object MUST have either stated OR understood one of these words: to, for, at, from. Now let's look at the sentences. I'll do #11 for you and then you try the rest, which I shall check for you later.
#11. = He asked her for more money. STOP. WHAT did he ask for? money = the direct object = he asked (past tense) for IT. NOW, WHOM (objective case because HE is the subject) did he ask? her Restate it and you get "He ask for the money FROM her." "her" must be the indirect-object pronoun.
Put it all together, and when you get to sentences with BOTH the direct and indirect, notice that I listed the Indirect BEFORE the Direct.
El le pidió más dinero.
Think you understand it? Try "walking through asking WHAT & from/of WHOM" to easily identivy what you are working with!