J’aime les gens sincères, même quand ils ne sont pas d’accord avec moi.

Because je contracts to j’ before a vowel sound.

• je + aime becomes j’aime
• This is very common in French: j’ai, j’habite, j’écoute

It helps the sentence sound smoother.

Les gens is a very common way to say people in general.

In this sentence, les gens sincères means sincere people as a general category, not a specific group you already know.

A few notes:

• les gens is extremely natural in everyday French
• des personnes sincères is possible, but sounds more formal or less common here
• Even though les often means the, French often uses it where English uses no article at all for general statements

So:

• J’aime les gens sincères = I like sincere people

Because in French, most adjectives come after the noun, and sincère is one of them.

So:

• des gens sincères = sincere people

Some adjectives come before the noun, but sincère normally does not.

Because it agrees with gens, which is plural.

• singular: un homme sincère
• plural: des hommes sincères

Here, gens is plural, so sincère becomes sincères.

Also note:

• sincère has the same form in masculine and feminine singular
• only the plural adds -s

Gens is plural. It means people.

So it takes:

• plural articles: les gens
• plural verbs when it is the subject: les gens sont
• plural adjectives: les gens sincères

In your sentence, gens is not the subject of the second clause, but it is still plural in les gens sincères.

Même quand means even when.

It introduces a situation that does not change the speaker’s opinion.

So the idea is:

• I like sincere people
• even when they disagree with me

Related expressions:

• quand = when
• même si = even if
• même quand = even when

In this sentence, même quand fits because it refers to a real or repeated situation.

That is the standard French negation: ne ... pas.

• ils sont d’accord = they agree
• ils ne sont pas d’accord = they do not agree

French usually puts:

• ne before the conjugated verb
• pas after it

Here the verb is sont from être, so:

• ils ne sont pas

In informal spoken French, people often drop ne and say:

• ils sont pas d’accord

But in correct written French, ne ... pas is expected.

Because the fixed expression is être d’accord avec quelqu’un, which means to agree with someone.

So you say:

• Je suis d’accord. = I agree.
• Ils sont d’accord avec moi. = They agree with me.
• Ils ne sont pas d’accord avec moi. = They do not agree with me.

You generally learn d’accord as one whole expression.

Because after a preposition like avec, French uses a stressed pronoun, not a subject pronoun.

So:

• subject pronoun: je
• stressed pronoun: moi

After avec, you must use:

• avec moi = with me
• avec toi = with you
• avec lui = with him
• avec elle = with her

So avec je is not grammatical.

Yes, it could be elles in some contexts, but ils is the normal default for a mixed or unspecified group.

Since les gens means people in general, French usually uses ils to refer back to it.

So:

• les gens ... ils ... = normal general reference

You might see elles only if the group is specifically all female.

Both are in the present tense.

• j’aime = I like / I love
• ils sont = they are

French often uses the present tense where English also uses the present.

Here:

• J’aime comes from aimer
• sont comes from être

Literally, aimer can mean both to like and to love, depending on context.

In this sentence, J’aime les gens sincères is naturally understood as I like sincere people, not I love sincere people.

That is because the object is a general category of people, not a romantic or strongly emotional context.

A natural approximate pronunciation is:

zhem lay zhawn sank-sehr, mem kon teel nuh son pah dah-kor av-ek mwa

A few sound notes:

• J’aime sounds like zhem
• les gens has a nasal vowel in gens
• sincères ends with a pronounced -r sound
• ils ne sont pas often links smoothly in speech
• d’accord begins with a d sound attached to accord

In more natural speech, some sounds may blend together, and ne may be reduced or dropped informally.

The comma separates the main idea from the added clause.

Main clause:

• J’aime les gens sincères

Added idea:

• même quand ils ne sont pas d’accord avec moi

It is similar to English punctuation in a sentence like:

• I like sincere people, even when they disagree with me.

The comma helps readability, though punctuation can sometimes vary slightly depending on style.