I don't understand why "prends-lui deux" can be a correct solution

Hello Ron,

I still don't understand your answer as "lui" is a pronoun for people, we are talking about bonbons which are things so shouldn't it be: "Prends-en deux"?

Thy, you are correct, lui is a pronoun for him or her.  In French, lui is the indirect object pronoun for both him and her. It is used for verbs following the preposition à, which means to or at. For example: Je parle à Pierre -> Je lui parle. I speak to Pierre. I speak to him. Je parle à Marie -> Je lui parle. I speak to Marie. I speak to her.

I sense that your confusion is about the bonbons.  

«prends-lui deux» would translate as 
"take him two"  --> him referring to whoever is to receive the bonbons, the only reference in the phrase to the bonbons is "deux" indicating to take 2 bonbons.

Perhaps this will assist in clarifying the usage:

 voila, ici sont deux bonbons, prends-les à lui -->  voila, here are two sweets, take them to him

In this phrase, les is the pronoun for the bonbons and lui is the pronoun for who is receiving the bonbons

Hopefully this clarifies it a bi for you,

bonne chance en continuation

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ISBN  978-1260453416

by Annie Heminway (Author)