Le plombier dit que ce tuyau n’est plus étanche.

In French, singular countable nouns usually need a determiner, such as le, un, ce, etc.

So:

• le plombier = the plumber
• un plombier = a plumber

You normally cannot say just plombier as the subject of a sentence in standard French.

Dit is the third-person singular present form of the verb dire, which means to say or to tell.

So:

• je dis = I say
• tu dis = you say
• il/elle dit = he/she says

In this sentence, Le plombier dit... means The plumber says...

Que means that and introduces a subordinate clause.

So:

• Le plombier dit = The plumber says
• que ce tuyau n’est plus étanche = that this pipe is no longer watertight

Just like English often uses that, French uses que very commonly after verbs like:

• dire = to say
• penser = to think
• croire = to believe

French uses:

• ce before most masculine singular nouns
• cet before masculine singular nouns starting with a vowel or mute h
• cette for feminine singular
• ces for plural

Tuyau is masculine singular, but it starts with the consonant sound t, so you use ce:

• ce tuyau = this pipe

You would use cet in something like:

• cet homme = this man
• cet appartement = this apartment

This is because ne becomes n’ before a vowel sound.

Here:

• ne + est becomes n’est

This is called elision. French often drops the vowel in small words before another vowel sound:

• je aime becomes j’aime
• le ami becomes l’ami
• ne est becomes n’est

Ne ... plus means no longer or not anymore.

In this sentence:

• n’est plus étanche = is no longer watertight

It shows that something used to be true before, but is not true now.

Compare:

• Il est étanche. = It is watertight.
• Il n’est pas étanche. = It is not watertight.
• Il n’est plus étanche. = It is no longer watertight.

That last one suggests a change of state.

Both are negative structures, but they mean different things:

• ne ... pas = simple negation, not
• ne ... plus = no longer, not anymore

Examples:

• Ce tuyau n’est pas étanche. = This pipe is not watertight.
• Ce tuyau n’est plus étanche. = This pipe is no longer watertight.

So plus adds the idea that it used to be watertight before.

Étanche means something like:

• watertight
• airtight
• sealed
• leak-proof

The exact English translation depends on context.

With tuyau (pipe), étanche usually means that it does not leak.

So in this sentence, the plumber is saying the pipe is not sealed properly anymore or is leaking now.

Yes, étanche is an adjective, and it agrees with the noun it describes.

Here, tuyau is:

• masculine
• singular

The adjective form is:

• étanche for masculine singular
• étanche for feminine singular
• étanches for plural

So the singular masculine form is correct in:

• ce tuyau est étanche

If it were plural:

• ces tuyaux sont étanches

Because the subject of the second clause is ce tuyau, which is singular.

Breakdown:

• ce tuyau = this pipe
• est = is

So:

• ce tuyau est... = this pipe is...

If the subject were plural, the verb would change:

• ces tuyaux sont... = these pipes are...

In ne ... plus, plus is usually pronounced plu when it means no longer / not anymore.

So:

• n’est plus étanche is typically pronounced roughly like nay plu ay-tansh

Important: plus does not always sound the same in French. Its pronunciation changes depending on meaning and context.

For learners, the key point here is:

• in ne ... plus, you will very often hear plu rather than plus

Étanche is pronounced roughly like ay-tansh.

A few helpful points:

• é sounds like ay
• an is a nasal vowel, not a full an sound like in English
• che sounds like sh

So the ending is not pronounced like English ch in chair. It is a sh sound.

In informal spoken French, many speakers drop ne in everyday conversation.

So you may hear:

• Ce tuyau est plus étanche

But this can be ambiguous, because without ne, it may sound like:

• This pipe is more watertight

For that reason, context and pronunciation matter a lot. In careful speech and in writing, ne is kept:

• Ce tuyau n’est plus étanche

As a learner, it is safest to use the full written form.

Because this sentence follows a very common French pattern:

subject + verb + que + subject + verb + complement

So:

• Le plombier = subject
• dit = verb
• que = that
• ce tuyau = subject of the second clause
• n’est plus étanche = verb phrase + adjective

French and English often line up quite closely with this type of sentence:

• The plumber says that this pipe is no longer watertight.
• Le plombier dit que ce tuyau n’est plus étanche.

That makes this a nice sentence for seeing how French clauses are built.