Je conseille souvent à mon voisin de cuisiner avec moins d’épices, car il les trouve trop fortes.

Because conseiller often uses the pattern conseiller à quelqu’un de + infinitive when you are advising someone to do something.

So here:

• Je conseille à mon voisin de cuisiner... = I advise my neighbor to cook...

The à marks mon voisin as the person receiving the advice.

Compare:

• Je conseille ce restaurant à mon voisin. = I recommend this restaurant to my neighbor.
• Je conseille à mon voisin de cuisiner autrement. = I advise my neighbor to cook differently.

English does not need a preposition here, but French usually does in this structure.

After conseiller à quelqu’un, French normally uses de + infinitive to say what action is being advised.

So:

• conseiller à quelqu’un de faire quelque chose

In this sentence:

• Je conseille souvent à mon voisin de cuisiner...

That literally works like:

• I often advise my neighbor to cook...

This is a very common French pattern. English says advise someone to cook, but French says conseiller à quelqu’un de cuisiner.

In French, short adverbs like souvent, toujours, déjà, and bien often come right after the conjugated verb in a simple tense.

So:

• Je conseille souvent...

is the most natural neutral order.

You could also say:

• Souvent, je conseille à mon voisin...

but that changes the emphasis a little. It sounds more like Often, I advise my neighbor...

After expressions of quantity like moins de, plus de, beaucoup de, peu de, French normally uses de (or d’ before a vowel), not an article like des.

So:

• moins d’épices = fewer/less spices

Other examples:

• beaucoup de sucre
• plus de légumes
• peu d’eau

Also, even though English often distinguishes less and fewer, French usually just uses moins for both countable and uncountable nouns:

• moins d’épices
• moins d’eau

Because d’ here is just the shortened form of de before a vowel sound.

So:

• de épices becomes d’épices

The plural is still shown by épices, not by d’.

This is just elision, the same thing you see in:

• l’eau instead of le eau
• j’aime instead of je aime

Les is a direct object pronoun replacing les épices.

Instead of repeating the noun, French uses the pronoun:

• il trouve les épices trop fortes
• il les trouve trop fortes

In French, object pronouns usually come before the conjugated verb, which is different from English.

So:

• les = them
• il les trouve = he finds them

Because fortes agrees with épices, which is feminine plural.

• singular: une épice forte
• plural: des épices fortes

In il les trouve trop fortes, the adjective still refers to les épices, so it must stay feminine plural.

This is important: after verbs like trouver, juger, or considérer, an adjective describing the object often agrees with that object.

So:

• Il les trouve trop fortes.
• He finds them too strong.

Since them = épices, the adjective is fortes.

Because trouver shows a person’s perception, judgment, or opinion.

• Il les trouve trop fortes = He finds them too strong.
• Elles sont trop fortes = They are too strong.

The first version focuses on his reaction to the spices. The second sounds more like a direct statement of fact.

So trouver is useful when you want to express what someone thinks or feels about something.

Both car and parce que can mean because, but they are not used in exactly the same way.

In this sentence:

• car il les trouve trop fortes

Car introduces an explanation. It often sounds a little more formal or written than parce que.

So:

• Je conseille souvent à mon voisin de cuisiner avec moins d’épices, car il les trouve trop fortes.

is perfectly natural, especially in writing.

In everyday speech, many people would more often say:

• ... parce qu’il les trouve trop fortes.

So the difference here is mainly one of style and register, not meaning.

Because voisin is the masculine form of the noun, so it refers to a male neighbor.

• mon voisin = my male neighbor
• ma voisine = my female neighbor

The possessive also changes with the noun:

• mon voisin
• ma voisine

So this sentence specifically tells us the neighbor is male.

Yes. Fort can have several related meanings depending on context, and with food it often means something like:

• strong-tasting
• overpowering
• spicy
• hot

So in des épices trop fortes, it does not mean physically strong. It means the spices have too intense a flavor or heat for him.

This is very common in French with food, smells, coffee, alcohol, and seasoning:

• un café trop fort = coffee that is too strong
• une sauce trop forte = a sauce that is too strong/spicy
• des épices trop fortes = spices that are too strong/spicy