Learn French: Ils la lui font lire. - They are having him read it.

Normally, object pronouns go right before the infinitive (like ils veulent la lire). However, the causative faire construction acts as a single, inseparable block. Because of this rule, any pronouns belonging to the action must be placed before the conjugated form of faire.

Why do we use the indirect pronoun lui for 'him', when the English sentence says 'have him read'?

This is the trickiest rule of the causative faire. When the infinitive (lire) has a direct object (here, la, meaning the thing being read), the person performing the action (the agent) is forced to become an indirect object. Since the direct object slot is taken by la, the agent becomes the indirect lui.

Why is the pronoun order la lui instead of lui la?

In French, when you have two third-person pronouns together, the direct object (le, la, les) always precedes the indirect object (lui, leur). So we get la lui. If the indirect object were a first or second person (like me or vous), it would come first, as in Ils me la font lire.

Could this sentence also mean 'They are having her read it'?