How do you know what to do with the past participle when you have multiple pronouns in a sentence?

A direct object changes the past participle, an indirect one does not. A simple sentence which you can remember to help with this is 'I gave it to you'. 'It' is the direct object as it is the thing being handled directly. 'You' are the indirect object, you are being affected as a result, therefore 'indirectly'. A big clue here is the 'to' in front of 'you'.Spot the direct object and indirect objects in these sentences (clue - some contain both and some only contain one): I spoke to you. I have the book. We saw him. Now back to the sentence 'I gave it to you'. If the direct object is feminine, we put an 'e' on the end of the past participle of 'donner', just like we would with an adjective. If the 'it' is masculine then we don't put anything on the end, again just like with adjectives. For example: ‘Je te l’ai donnée’ (the 'it' is feminine, la pomme, la femme, etc.), whereas ‘Je te l’ai donné’ (the 'it' is masculine', le pantalon, le poisson, etc.)