Je centre l’argile du moment que la girelle tourne.

It is a verb here.

• The infinitive is centrer = to center
• Je centre = I center / I am centering

So in this sentence, centre is the 1st person singular present tense form of centrer.

Because French uses elision: la becomes l’ before a vowel sound.

• la + argile → l’argile

This is very common in French:

• l’eau
• l’école
• l’idée

So l’argile is just the normal form of the clay.

French often uses an article where English might not.

In English, we often say simply clay as a material. In French, it is very natural to say l’argile when talking about the clay being worked.

So l’argile does not necessarily sound extra specific; it is just normal French usage.

Du moment que is a fixed expression. Its meaning depends on context, but common meanings are:

• as long as
• while
• sometimes since, in the sense of given that

In this sentence, it most naturally expresses a condition or time frame: the action of centering happens as long as / while the wheelhead is turning.

So it is not a word-for-word phrase you should translate mechanically. Learn it as a chunk: du moment que.

Yes, but it has a slightly specific feel.

It is common enough, especially in speech and writing, but learners should know that in some contexts French might also use:

• tant que = as long as / while
• lorsque = when
• pendant que = while

The best choice depends on the exact meaning.

• tant que often emphasizes for as long as
• pendant que focuses more on simultaneous actions
• du moment que can suggest from the moment that, as long as, or given that, depending on context

So du moment que is natural, but it is not the only possible phrasing.

Tourne is the 3rd person singular present form of tourner = to turn / to spin.

It matches the subject la girelle, which is singular:

• la girelle tourne = the wheelhead is turning / turns

Conjugation of tourner in the present:

• je tourne
• tu tournes
• il / elle tourne
• nous tournons
• vous tournez
• ils / elles tournent

So tourne is used because the subject is la girelle.

In pottery vocabulary, la girelle refers to the turning plate / wheelhead of a potter’s wheel.

Important point:

• it does not always mean the entire pottery wheel
• it often means the rotating top part on which the clay sits

So if you already know the general meaning of the sentence, this word is a more technical pottery term.

Because French uses the simple present for several ideas that English often separates.

Je centre can mean:

• I center
• I am centering

And la girelle tourne can mean:

• the wheelhead turns
• the wheelhead is turning

French does not need a separate form like English am + -ing in most ordinary cases. The present tense often covers both meanings.

Yes, it could.

Être en train de + infinitive means to be in the middle of doing something, and it emphasizes the ongoing action.

So:

• Je centre l’argile = I center / I am centering the clay
• Je suis en train de centrer l’argile = I am in the process of centering the clay

The original sentence is more neutral and more concise. French usually prefers the simpler present unless there is a reason to stress that the action is happening right now.

Here it takes the indicative, which is why you see tourne.

That is normal, because the sentence describes a real situation or condition, not something doubtful, emotional, or hypothetical in the way that often triggers the subjunctive.

So:

• du moment que la girelle tourne

with tourne as present indicative is exactly what you would expect.

Yes.

You could also say:

• Du moment que la girelle tourne, je centre l’argile.

That is grammatically fine. It just changes the emphasis slightly.

• Original order starts with what I do
• Reversed order starts with the condition or circumstance

French allows both.

A careful pronunciation is approximately:

Je centre l’argile du moment que la girelle tourne
/ʒə sɑ̃tʁ laʁ.ʒil dy mɔ.mɑ̃ kə la ʒi.ʁɛl tuʁn/

A few useful notes:

• je often sounds like zhuh
• centre has a nasal vowel: sahntr
• l’argile begins directly with the a sound after the l’
• girelle begins with the zh sound, like the s in measure
• tourne sounds roughly like toorn, but with a French r

In natural speech, some unstressed e sounds may weaken or disappear.

Yes: it looks familiar, but here it is a verb form, not the noun center/centre.

English speakers may recognize centre as a noun because of British spelling, but in French:

• un centre = a center
• je centre = I center

Same spelling, different grammatical role.

So you have to identify it from the sentence structure:

• Je
  • verb form → centre must be the verb here.