Learn Hardcore French: Paul tient le sac contre son ventre. - Paul holds the bag against his stomach.

This sentence suggests a particular bag that is already known in the context (for example, the bag we’ve been talking about). French normally uses the definite article (le / la / les) when the object is specific or already identified.

If you said Paul tient un sac contre son ventre, it would mean Paul is holding a bag (some bag or an unknown bag) against his stomach, which changes the nuance.

Why is it son ventre and not sa ventre?

In French, the possessive adjective (son / sa / ses) agrees with the gender and number of the noun possessed, not with the person who owns it.

ventre (stomach/belly) is masculine singular → you must use son.
So you say son ventre, no matter whose stomach it is (Paul’s, Marie’s, etc.).

Examples:

son ventre = his/her stomach (because ventre is masculine)
sa main = his/her hand (because main is feminine)
ses mains = his/her hands (plural)

Could we say son sac instead of le sac?

Yes, son sac is grammatically correct; it just emphasizes that the bag belongs to Paul (or to someone else previously mentioned).

Paul tient le sac contre son ventre.
→ Paul is holding the bag (the specific bag we know about).
Paul tient son sac contre son ventre.
→ Paul is holding his bag against his stomach.

Both are possible; the choice depends on whether the context cares about possession or just about which bag we’re talking about.

What exactly does tenir mean here, and how is it different from porter?

In this sentence, tenir means to hold (keeping something in your hands or close to your body).

tenir = to hold (keep in a certain position, often with your hands)
→ Paul tient le sac contre son ventre. = Paul is holding the bag against his stomach.
porter = to carry (transport something from one place to another, or wear clothes)
→ Paul porte un sac. = Paul is carrying a bag / wearing a bag.

So:

Use tenir when focusing on the position or grip on something.
Use porter when focusing on carrying or wearing something (a bag, clothes, glasses, etc.).

How is tenir conjugated in the present tense?

Tenir is an irregular verb. In the present tense:

je tiens
tu tiens
il / elle / on tient
nous tenons
vous tenez
ils / elles tiennent

In the sentence Paul tient le sac contre son ventre, tient is 3rd person singular (like il tient), because it refers to Paul.

What does contre mean here, and what other prepositions could be used?

Here, contre means against, in the sense of pressed against / touching.

Paul tient le sac contre son ventre.
= Paul holds the bag against his stomach (the bag is touching his body).

Other possibilities (with slightly different meanings):

sur = on / on top of
→ Paul tient le sac sur ses genoux. = Paul holds the bag on his knees.
près de = near / close to
→ Paul tient le sac près de son ventre. = He holds the bag near his stomach (not necessarily touching).

So contre emphasizes contact (bag is pushed or resting against his body).

Why do we need a preposition like contre here? Could we say Paul tient le sac son ventre?

You must use a preposition in French to express the relationship between the bag and the body part.

Paul tient le sac son ventre is incorrect.
You need contre, sur, près de, etc. to link le sac and son ventre:

Correct examples:

Paul tient le sac contre son ventre.
Paul tient le sac sur son ventre.
Paul tient le sac près de son ventre.

French does not allow you to place two nouns together like that (bag + stomach) without a preposition or some other link.

What’s the difference between ventre, estomac, and bidon?

All three relate to the idea of “stomach/belly,” but they’re used differently:

ventre
- Most common, neutral word for belly / stomach area.
- Used in everyday speech and in this kind of physical description.
- Paul tient le sac contre son ventre.
estomac
- Refers more to the internal organ (stomach).
- Often used in medical or more literal physical contexts.
- J’ai mal à l’estomac. = I have a stomachache (the organ).
bidon (very informal / slang)
- Means belly / tummy / gut, often with a slightly joking or negative tone (big belly, potbelly).
- Il a un gros bidon. = He has a big belly.

In this sentence, ventre is the natural, neutral choice.

How do you pronounce tient, contre, and ventre?

Approximate pronunciations (French IPA + simple description):

tient → /tjɛ̃/
- Like tyeh̃, one syllable.
- ti- like tee but quickly followed by a y sound (like ty in tune in some accents).
- -ent here is a nasal vowel ɛ̃ (like en in French but more nasal); the -nt is silent.
contre → /kɔ̃tʁ/
- con-: kɔ̃, nasal sound like con in French bonjour’s bon.
- Final -tre: the r is pronounced in the throat; the e is practically silent.
- Roughly like kohn-tr in one syllable and a half.
ventre → /vɑ̃tʁ/ (often /vɑ̃tʀ/ depending on accent)
- ven-: vɑ̃, nasal; a bit like “vahn”.
- Final -tre: again, audible r, almost no vowel.
- Roughly vahn-tr.

All three have a nasal vowel (written -en, -on, -en), where air passes through the nose and the final consonant letter is not fully pronounced as in English.

Could the word order be Paul tient contre son ventre le sac, or is that wrong?

Paul tient contre son ventre le sac is grammatically possible but sounds very unusual and stylistic/poetic in modern French.

Normal, natural word order:

Paul tient le sac contre son ventre.

In everyday French, the direct object (le sac) almost always comes right after the verb, and any extra phrase (like contre son ventre) comes after the object.

How would you say this sentence in the negative, or in the past tense?

Negative (present tense):

Paul ne tient pas le sac contre son ventre.
= Paul is not holding the bag against his stomach.

Compound past (passé composé):

Paul a tenu le sac contre son ventre.
= Paul held the bag against his stomach.

Negative in the passé composé:

Paul n’a pas tenu le sac contre son ventre.
= Paul did not hold the bag against his stomach.

Note:

ne … pas usually goes around the conjugated verb (in the passé composé, around the auxiliary avoir).