Le sablier mesure le temps du tour de jeu.

Sablier means hourglass or sand timer.

It is masculine, so it takes le in the singular:

• le sablier = the hourglass
• un sablier = an hourglass

That is why the sentence starts with Le sablier.

Yes. Here mesure is the verb mesurer in the present tense, third person singular:

• je mesure = I measure
• tu mesures = you measure
• il / elle / on mesure = he / she / one measures

Since the subject is Le sablier (singular), French uses mesure.

So:

• Le sablier mesure... = The hourglass measures...

French often uses the definite article where English may not.

Here, le temps means the time in a general but still grammatically definite way. French usually prefers the article in this kind of structure:

• mesurer le temps = to measure time / to measure the time

Even if English might sometimes say just measure time, French normally says mesurer le temps.

Yes, temps can mean both time and weather, depending on context.

For example:

• le temps passe = time passes
• Il fait beau temps = the weather is nice

In this sentence, because of mesure and the game context, temps clearly means time, not weather.

Du is the contraction of de + le.

So:

• de le becomes du

In this sentence:

• du tour de jeu = of the game turn

French requires this contraction before a masculine singular noun:

• de + le sablier → du sablier
• de + le tour → du tour

So du here means of the.

Tour de jeu means game turn, turn of play, or sometimes round depending on context.

The key word is tour, which has several meanings in French. Here it means a turn in a game: the period when a player acts.

So:

• un tour = a turn
• un tour de jeu = a turn in the game / a game turn

This is a common board-game or rulebook expression.

This is a very common learner question.

• tour de jeu means something like game turn or turn of play
• tour du jeu would more literally mean the turn of the game

In tour de jeu, de jeu works almost like a label or category: it tells you what kind of tour it is.

Compare:

• une table de cuisine = a kitchen table
• un tour de jeu = a game turn

If you said du jeu, that would sound more like you are referring to the game as a specific thing owning or defining the turn.

So tour de jeu is the more natural expression for game turn.

The structure is very straightforward French:

• Le sablier = subject
• mesure = verb
• le temps du tour de jeu = object

Inside that object:

• le temps = the time
• du tour de jeu = of the game turn

So the sentence follows the normal French pattern:

subject + verb + object

That makes it quite close to English word order.

Yes, and that can confuse learners.

Tour can mean different things, including:

• a turn
• a trip / a walk around
• a trick
• a tower in some cases, but that is actually a different noun: la tour (feminine)

So the article matters:

• le tour = turn / trip / trick
• la tour = tower

In du tour de jeu, it is le tour, so it means turn.

A simple pronunciation guide is:

Le sablier mesure le temps du tour de jeu
luh sa-blee-ay muh-zur luh tahn dy toor duh zhuh

A few helpful notes:

• sablier ends with a sound like -yé
• mesure has a u sound that does not exist exactly in English
• temps has a nasal vowel; the final ps is not pronounced
• jeu sounds roughly like zhuh with rounded lips

If you want a more IPA-style version:

[lə sa.blje mə.zyʁ lə tɑ̃ dy tuʁ də ʒø]

Yes. In context, mesurer le temps can mean to measure the duration of something, which is close to English to time.

So here the idea is that the hourglass is being used to track how long the turn lasts.

That is why this sentence sounds natural in game instructions or rules.

Yes, it is understandable and natural in a rules or instruction context.

It sounds like the kind of sentence you might find in:

• a board-game rulebook
• game instructions
• a classroom activity using a timer

It has a slightly explanatory or formal feel, which fits that kind of context well.