En avril, s’il ne pleut pas, nous irons au marché de Pâques sur la place du village.

En avril means in April. In French, months are normally used with en when you mean in a given month:

• en avril = in April
• en mai = in May
• en décembre = in December

Unlike English, French month names are usually not capitalized, so avril stays lower-case.

S’il means if he/it here, but in this sentence it is part of the weather expression il pleut.

It is a contraction of:

• si + il → s’il

French often uses an apostrophe when one word ending in a vowel comes before another word beginning with a vowel. This is called elision.

So:

• si il ne pleut pas → s’il ne pleut pas

In il pleut, il does not refer to a person or thing. It is an impersonal subject, like English it in it is raining.

So:

• il pleut = it is raining
• il neige = it is snowing
• il fait froid = it is cold

The il is required by French grammar even though it does not point to anything specific.

This is the normal French negation pattern:

• ne ... pas

The positive form is:

• il pleut = it is raining

The negative form is:

• il ne pleut pas = it is not raining / it does not rain

In everyday spoken French, people often drop ne and say il pleut pas, but in standard written French you normally keep both parts.

Irons is the future simple of aller for nous:

• je irai
• tu iras
• il/elle ira
• nous irons
• vous irez
• ils/elles iront

The sentence is talking about something that will happen later: we will go. So French uses the future here, just as English does in we will go.

This is a very important French rule:

After si meaning if, French does not use the future when talking about a real possible condition.

So French says:

• Si + present, future
• s’il ne pleut pas, nous irons
  = if it doesn’t rain, we will go

Not:

• si il ne pleuvra pas ❌

This is one of the biggest differences from English, because English allows if it doesn’t rain, we’ll go, but French must keep the verb after si in the present.

Au is a contraction of:

• à + le → au

After aller, à is used to say where you are going:

• aller au marché = to go to the market

So:

• nous irons au marché de Pâques = we will go to the Easter market

Marché de Pâques literally means market of Easter, which is how French expresses Easter market.

English often puts one noun directly before another noun:

• Easter market
• village square
• Christmas song

French usually links nouns with de instead:

• marché de Pâques = Easter market
• place du village = village square
• cadeau de Noël = Christmas present

So de is a very common way to connect two nouns in French where English might use a noun as an adjective.

Here place means square, not place in the general English sense.

So:

• la place du village = the village square

French often uses sur for something set up or happening on/in the square, especially markets, festivals, stands, and public events.

So:

• sur la place du village = on the village square / in the village square

It may sound more natural in English to say in the village square, but French commonly uses sur in this context.

Du is a contraction of:

• de + le → du

So:

• la place du village literally = the square of the village

In smoother English, that becomes:

• the village square

This same contraction appears very often in French:

• le centre du village = the center of the village
• la porte du jardin = the garden gate
• le toit du garage = the roof of the garage

The commas help separate the introductory parts of the sentence:

• En avril, = time setting
• s’il ne pleut pas, = condition
• nous irons... = main clause

French punctuation here works much like English punctuation. The commas make the structure clearer and easier to read.

Without them, the sentence would still be understandable, but with them it is more natural and organized.

In French, names of months and days are normally not capitalized:

• avril
• lundi
• octobre

But names of major holidays such as Pâques are usually capitalized:

• Pâques
• Noël

So the spelling in the sentence is normal French usage.