La tache de café part vite avec un chiffon humide.

Because tache meaning stain is a feminine noun in French, so it takes la in the singular.

• la tache = the stain
• une tache = a stain

Be careful not to confuse it with le tâche, which is not correct. Also note the very similar word la tâche with a circumflex accent, which usually means task or job.

This is a very common question because the words look almost the same.

• tache = stain, spot, mark
• tâche = task, job, assignment

So in this sentence:

• La tache de café = The coffee stain

not:

• La tâche de café = which would not make sense here

In modern writing, the accent matters for meaning.

French often uses de where English uses a noun directly before another noun.

So:

• une tache de café = a coffee stain
• literally: a stain of coffee

This is a very common French pattern:

• une tasse de thé = a cup of tea
• une bouteille d’eau = a bottle of water
• une table de cuisine = a kitchen table

English often stacks nouns together; French usually connects them with de.

Here, de café describes the type or source of the stain: a stain caused by coffee.

• une tache de café = a coffee stain

French usually uses de after a noun when the second noun identifies what kind of thing it is.

Compare:

• une tasse de café = a cup of coffee
• une odeur de café = a smell of coffee
• une tache de café = a coffee stain

Using du café here would sound less natural in standard usage.

Yes, and that is exactly why this can confuse learners.

Partir usually means to leave, but with stains, dirt, marks, and similar things, French uses partir to mean:

• to come out
• to go away
• to disappear

So:

• La tache part = The stain comes out / goes away

This is a very natural French way to talk about whether a stain can be removed.

Examples:

• Cette tache ne part pas. = This stain won’t come out.
• Le gras part difficilement. = Grease comes off with difficulty.

Because the subject is la tache, which is third person singular.

The verb is partir, and in the present tense:

• je pars
• tu pars
• il / elle / on part
• nous partons
• vous partez
• ils / elles partent

Since la tache is like elle, the correct form is part.

Vite means quickly.

In this sentence:

• La tache de café part vite = The coffee stain comes out quickly

French adverbs like vite often come after the verb, especially in simple sentences.

So the order is very natural:

• subject + verb + adverb
• La tache ... part vite

Compare:

• Il parle vite. = He speaks quickly.
• Ça sèche vite. = That dries quickly.

Because avec can express several ideas, including:

• with = accompaniment
• with = means/instrument

Here it expresses the means used to remove the stain:

• avec un chiffon humide = using a damp cloth

So the sentence means the stain comes out when you use a damp cloth.

This is similar to:

• couper avec un couteau = to cut with a knife
• écrire avec un stylo = to write with a pen

Because humide is the normal adjective meaning damp or moist.

It agrees with chiffon, which is masculine singular, but in this case the masculine and feminine singular forms are spelled the same:

• un chiffon humide
• une serviette humide

So there is no extra ending to add here.

Un chiffon usually means a cloth, rag, or cleaning cloth.

In this sentence, it suggests a cloth used for cleaning, not an elegant fabric napkin.

So:

• un chiffon humide = a damp cloth / damp rag

Depending on context, English might translate it differently, but damp cloth is a very natural choice here.

Because after de, when one noun describes another, French often uses the second noun without an article.

So:

• une tache de café
• une tasse de thé
• une odeur de fumée

This is just the normal pattern for noun + de + noun.

If you said de le café, it would contract to du café, but that is not the structure being used here.

It can work as a general statement, especially in practical contexts like cleaning instructions.

French often uses the definite article in general statements where English may also use the or sometimes a depending on style.

So La tache de café part vite avec un chiffon humide can mean something like:

• Coffee stains come out quickly with a damp cloth
• or The coffee stain comes out quickly with a damp cloth

The exact English wording depends on context, but the French sentence is perfectly natural as a general fact.

Yes, but part is especially common and idiomatic for stains.

Possible alternatives:

• La tache disparaît vite = The stain disappears quickly
• La tache s’en va vite = The stain goes away quickly

However, partir is one of the most natural verbs when talking about whether a stain washes out or comes off.

So La tache de café part vite sounds very idiomatic in everyday French.

A simple pronunciation guide is:

La tache de café part vite avec un chiffon humide.
la tash duh ka-fay par veet a-vek uh(n) shee-fon u-meed

A few notes:

• tache sounds like tash
• café has stress at the end: ka-FAY
• part is pronounced par; the final t is silent
• vite sounds like veet
• humide begins with a silent h, so it sounds like u-meed

French pronunciation varies by accent, but this will get you close.