berryspecial

[meager aurora]

Please be patient

Our volunteers look into many questions every day; sometimes it takes them a little while to answer.

Pro tip: you can rename the thread title with `.tr <thread name>`

Make it descriptive, including relevant context, but also to the point. This way you improve your chances of getting a more relevant and specific answer.

[lusty silo]

Je parle à mon frère => je lui parle
Je parle de mon frère => je parle de lui
Je parle du livre (an inanimate object) => j'en parle

[opaque jungle]

Thank you, so if the indirect object after de is a human then I use the construction de lui and if it's an object I use en and this is in general not just this specific case ?
So for I neglect my brother: Je manquer de mon frère -> Je manquer de lui ?

[lusty silo]

We don't say "je manque de mon frère" at all. The expression manquer de in the meaning you gave is followed by an infinitive clause.
I neglect my brother => je néglige mon frère.

[opaque jungle]

ok, thank you !

[lusty silo]

Anyway, to use another expression using de:
J'ai besoin de mon frère => j'ai besoin de lui
J'ai besoin du livre => j'en ai besoin

[opaque jungle]

ok, I see the pattern now, thank you

[sick saddle]

Indirect objects just mean that the objects are not alone, they are preceded by a preposition

It doesn't matter what preposition it is; as long as there is one, it's indirect.
Je parle à Émile = Indirect
Il a du mal avec son patron = Indirect
Ils s'occupent de leurs enfants = Indirect
Elle a fait des recherches sur la nouvelle employée = Indirect
Il a acheté un cadeau pour son mari = Indirect

The difference is that most of them are unable to be replaced by the indirect object pronoun (lui/leur). That only works for « à / pour ».