À la récréation, mon copain court partout.

À la récréation sets the time: at recess or during recess.

French often puts a time expression at the beginning of a sentence for context, just like English can do with At recess, ... or During recess, ....

The basic sentence is:

Mon copain court partout.
= My friend runs everywhere.

Adding À la récréation tells you when this happens.

Because à la récréation is the natural idiomatic expression.

In French, à is often used in time expressions like this to mean at or during a certain moment or event.

So:

• à la récréation = at recess / during recess

Dans la récréation would sound unnatural here.

You could also hear:

• pendant la récréation = during recess

That is also correct, but à la récréation is a very common school-context expression.

In a school context, la récréation means recess, break time, or playtime, depending on the variety of English.

So for an English speaker:

• American English: recess
• British English: often break or playtime

It usually refers to the break when children go out and play.

Copain can mean friend, mate, pal, or sometimes boyfriend, depending on context.

In this sentence, because of the school setting (À la récréation) and the simple phrasing, mon copain will most naturally be understood as my friend.

Important nuance:

• un copain = a male friend / buddy
• mon copain can sometimes mean my boyfriend

So yes, the phrase can be ambiguous in some situations, but here my friend is the most likely meaning.

Because copain is a masculine noun.

In French, the possessive adjective agrees with the noun possessed, not with the speaker.

So:

• mon copain = my male friend
• ma copine = my female friend

Even if the speaker is female, she would still say mon copain if she is talking about a masculine noun.

Because court is the conjugated verb, while courir is the infinitive.

The verb is courir = to run.

In the present tense:

• je cours
• tu cours
• il/elle/on court
• nous courons
• vous courez
• ils/elles courent

Since mon copain is he / one person, French uses the third-person singular form:

• mon copain court = my friend runs

Court is pronounced roughly like koor in English, but with a French r sound: /kuʁ/.

A few useful points:

• the t at the end is silent
• it sounds the same as cour in normal pronunciation

So court is written with -t, but you do not pronounce that final letter.

Because court already means runs.

In English, he runs uses one word for the action. French does the same:

• court = runs

So:

• mon copain court = my friend runs

There is no need for a separate word like is unless you are using a different structure, such as is running.

Partout is an adverb meaning everywhere or all over the place.

It describes where or in what way he is running:

• mon copain court partout = my friend runs everywhere

Since partout is an adverb, it does not need an article like the or a.

Because that is the normal position for this kind of adverb in French.

French often places adverbs like partout, vite, bien, etc. after the verb:

• Il court partout.
• Elle parle vite.

So:

• mon copain court partout is the natural word order

You could move things around for emphasis in some contexts, but this is the standard and most neutral version.

It is not absolutely required in every case, but it is very natural here.

The comma helps separate the introductory time phrase from the main sentence:

• À la récréation, mon copain court partout.

Without the comma, the sentence is still understandable:

• À la récréation mon copain court partout.

But the comma makes it clearer and more polished in writing.

Yes. That is also correct.

Both of these are fine:

• À la récréation, mon copain court partout.
• Mon copain court partout à la récréation.

The difference is mainly emphasis:

• À la récréation, ... highlights the time first
• Mon copain court partout à la récréation starts with the subject and sounds a bit more neutral

Because récréation is a feminine singular noun beginning with a consonant.

The forms are:

• à + le = au
• à + la = à la
• à + l' before a vowel sound

So:

• le parc → au parc
• la récréation → à la récréation
• l'école → à l'école

Since it is la récréation, the correct form is à la récréation.