La partie commence avec ton tour de jeu.

Here, la partie means the game, the match, or the round, depending on context.

French often uses partie for a session of play:

• une partie d’échecs = a game of chess
• une partie de cartes = a card game / a round of cards

So la partie commence means the game is starting.

Because partie is a feminine noun in French.

That is why it takes:

• la partie = the game
• une partie = a game

This is something you simply have to learn with the noun.

Because the verb is conjugated.

The base form is commencer = to start / to begin.

In the sentence, the subject is la partie, which is third person singular, so the verb becomes:

• la partie commence = the game starts

A quick comparison:

• commencer = to start
• je commence = I start
• tu commences = you start
• la partie commence = the game starts

In this sentence, tour means turn, as in a player's turn in a game.

So:

• ton tour = your turn

Be careful: tour can have several meanings in French depending on context:

• une tour = a tower
• un tour = a turn, a trip, a trick, a round, etc.

Here it is un tour, the masculine noun meaning turn.

Ton tour de jeu means your turn to play or your game turn.

Very often, French speakers would simply say ton tour, because the game context already makes the meaning clear:

• C’est ton tour. = It’s your turn.

Adding de jeu makes it more explicit and can sound more formal, instructional, or game-related:

• ton tour de jeu = your turn in the game

So yes, ton tour is often enough, but ton tour de jeu is not wrong.

Because ton goes with tour, and tour is masculine in this meaning.

So:

• ton tour = your turn

It does not agree with partie. It agrees with the noun it directly belongs to, which is tour.

De jeu means of play / in the game.

It specifies what kind of turn is being talked about. French often uses de + noun to define or narrow the meaning of another noun.

So:

• tour = turn
• tour de jeu = turn in the game / playing turn

Without de jeu, tour could still be understood, but de jeu adds precision.

Avec literally means with, so the sentence is structured like:

The game starts with your turn.

It tells you what the game begins with.

That said, a learner may notice that French often prefers other phrasing in this kind of context, for example:

• La partie commence par ton tour.
• Tu commences la partie.
• C’est toi qui commences.

So avec is understandable, but depending on context, par may sound more natural to many native speakers.

It is understandable, but it may sound a little stiff or less idiomatic depending on the situation.

More natural alternatives might be:

• La partie commence par ton tour.
• Tu commences.
• C’est ton tour de commencer.
• C’est toi qui commences.

If this comes from a game interface, rulebook, or translated text, La partie commence avec ton tour de jeu is plausible, but in everyday speech many native speakers would probably choose a simpler version.

French usually follows a basic pattern like:

subject + verb + complement

So here:

• La partie = subject
• commence = verb
• avec ton tour de jeu = complement

This is the most straightforward and neutral order.

You could move parts around for emphasis, but the standard order is the easiest and most common.

A simple pronunciation guide is:

la par-TEE co-MONSS a-VEK ton toor duh zhuh

A few useful notes:

• partie sounds roughly like par-tee
• commence ends with an s sound
• avec is usually pronounced a-vek
• tour rhymes roughly with poor in English, but with a French r
• jeu has no exact English equivalent; it sounds a bit like the vowel in sir but with rounded lips

If spoken naturally, the rhythm would be smooth: La partie commence avec ton tour de jeu.