Il y a un tuyau sous l’évier, et une goutte d’eau tombe toutes les minutes.

Il y a is the standard French way to say there is or there are.

So:

• Il y a un tuyau = There is a pipe
• Il y a des tuyaux = There are some pipes

It does not literally work the same way as English grammar, so it is best to learn il y a as a fixed expression.

Because tuyau is a masculine noun in French.

• un tuyau = a pipe
• le tuyau = the pipe

In French, every noun has a grammatical gender, so the article has to match the noun.

Because évier starts with a vowel sound, and in French le becomes l’ before a vowel or silent h.

So:

• le + évier becomes l’évier

This is called elision.

You will see the same thing in many places:

• l’eau
• l’école
• l’homme

Sous means under or beneath.

So sous l’évier means under the sink.

The article is there because French usually says under the sink, not just under sink. In many everyday location phrases, French keeps the article where English may or may not.

Because after a noun like goutte when you say what something is made of or consists of, French usually uses de.

So:

• une goutte d’eau = a drop of water
• un verre de lait = a glass of milk
• une bouteille de vin = a bottle of wine

Since eau begins with a vowel, de becomes d’:

• de eau is not used
• it becomes d’eau

Tomber is the infinitive, meaning to fall.

In the sentence, the verb has to be conjugated to match the subject une goutte d’eau, which is third person singular.

So:

• tomber = to fall
• une goutte d’eau tombe = a drop of water falls

Present tense of tomber:

• je tombe
• tu tombes
• il / elle tombe
• nous tombons
• vous tombez
• ils / elles tombent

Yes, in English we would often say a drop of water drips every minute or water drips every minute.

French often uses tomber literally, meaning to fall, for a drop coming down. So une goutte d’eau tombe is a natural way to express that idea.

Depending on context, French can also use verbs related to leaking or dripping, but tomber works well here because the focus is on each drop falling.

In French, every + unit of time is often expressed as:

tous les / toutes les + plural noun

So:

• toutes les minutes = every minute
• tous les jours = every day
• toutes les semaines = every week

Here, minutes is feminine plural, so French uses toutes.

This may feel strange because English uses singular in every minute, but French normally uses the plural structure here.

Because minute is a feminine noun.

• singular: la minute
• plural: les minutes

So the form of all/every must agree:

• toute la minute would not mean the same thing here
• toutes les minutes = every minute

Compare:

• tous les jours = every day, because jour is masculine
• toutes les heures = every hour, because heure is feminine

Yes. Chaque minute also means every minute.

Both are natural, but there is a slight stylistic difference:

• chaque minute = each minute / every minute
• toutes les minutes = every minute, with a more repeated, ongoing sense

In this sentence, both would work:

• Une goutte d’eau tombe chaque minute
• Une goutte d’eau tombe toutes les minutes

Because toutes les minutes refers to a repeated interval: one drop falls in each minute.

So the idea is:

• one drop
• in every minute
• again and again

French expresses this repetition with the plural time noun.

Because after goutte de, French does not use an article here.

It is the same pattern as:

• une tasse de café
• un kilo de pommes
• une goutte d’eau

So eau is introduced by de, not by la or l’.

The apostrophe shows that a vowel has been dropped, so these are pronounced smoothly:

• l’évier sounds roughly like lay-vyay
• d’eau sounds roughly like doh

A few useful pronunciation notes:

• évier has é like a clear ay sound
• the final r in évier is pronounced
• eau is pronounced like o

So une goutte d’eau flows together very smoothly in speech.