À l’université, je laisse mon surligneur et mon cahier dans mon casier avant d’aller au café.

À l’université means at the university or sometimes to the university, depending on context. In this sentence, it means at the university.

The structure is:

• à = at / to
• l’ = the (used before a vowel sound)
• université = university

So:

• à + l’université = at the university

The phrase is placed at the beginning to set the scene: At the university, ...

Because université starts with a vowel sound, French uses l’ instead of le or la.

So:

• la université ❌
• l’université ✅

This is called elision. French often drops the vowel in a short word like le, la, or de before another vowel sound.

Laisse is the je form of the verb laisser in the present tense.

The verb laisser means to leave or to leave behind.

Present tense:

• je laisse
• tu laisses
• il / elle / on laisse
• nous laissons
• vous laissez
• ils / elles laissent

So je laisse means I leave.

Here, laisser means to leave something somewhere.

So:

• je laisse mon surligneur et mon cahier dans mon casier
  = I leave my highlighter and my notebook in my locker

It does not mean to leave in the sense of departing. For that idea, French often uses partir or quitter, depending on the context.

In French, each singular countable noun normally needs its own determiner.

So French says:

• mon surligneur et mon cahier dans mon casier

not:

• mon surligneur et cahier ❌

Each noun gets its own my:

• mon surligneur = my highlighter
• mon cahier = my notebook
• mon casier = my locker

This is more natural and grammatically required in French.

Mon is the masculine singular possessive adjective meaning my.

Use:

• mon with a masculine singular noun
• ma with a feminine singular noun
• mes with a plural noun

Here:

• un cahier is masculine → mon cahier
• un casier is masculine → mon casier
• un surligneur is masculine → mon surligneur

A key point: in French, the possessive adjective agrees with the thing possessed, not with the owner.

So both a man and a woman would say:

• mon cahier = my notebook

Un surligneur means a highlighter.

It comes from the verb surligner, which means to highlight.

So:

• un surligneur = a highlighter pen / marker

It is a masculine noun, which is why the sentence uses mon surligneur.

Un cahier usually means a notebook or an exercise book.

It is a very common school-related word in French.

So:

• mon cahier = my notebook

It is masculine, so it takes mon.

Un casier means a locker.

So:

• dans mon casier = in my locker

It can also mean a storage compartment or a box in some contexts, but here locker is the natural meaning.

Because dans means in / inside, and that fits the idea of putting the items inside the locker.

• dans mon casier = in my locker

If you said à mon casier, that would sound more like at my locker or by my locker, not inside it.

So:

• dans = inside
• à = at / to

Because French uses avant de + infinitive to mean before doing something.

So:

• avant de partir = before leaving
• avant de manger = before eating
• avant d’aller = before going

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

• de aller ❌
• d’aller ✅

That is another example of elision.

After avant de, French normally uses the infinitive when the subject is the same as in the main clause.

Here the subject is je in both actions:

• je laisse ...
• before I go to the café

Since it is the same person doing both actions, French uses:

• avant d’aller au café = before going to the café

If the subject changed, French would usually use a different structure, often with avant que.

Because à + le contracts to au in French.

So:

• à le ❌
• au ✅

Examples:

• au café = to the café / at the café
• au restaurant = to the restaurant / at the restaurant

This is a very common contraction:

• à + le = au
• à + les = aux

In this sentence, aller au café means to go to the café.

With the verb aller, à / au usually marks the destination:

• aller au café = to go to the café

In other contexts, au café could also mean at the café, but with aller, the meaning is clearly to the café.

The comma separates the opening location phrase from the main clause.

• À l’université, je laisse...

This is similar to English:

• At the university, I leave...

The phrase at the beginning gives context first, and the comma helps mark that pause. It is not always absolutely required in every short sentence, but it is very natural here.

Yes. French word order is flexible enough that you could also say:

• Je laisse mon surligneur et mon cahier dans mon casier avant d’aller au café, à l’université.

But that version sounds less natural because à l’université works better as the setting at the beginning.

The original sentence is the most natural because it first tells you where the action happens, then what happens.

Because French uses possessive adjectives directly, just like English does.

So:

• mon surligneur = my highlighter
• mon cahier = my notebook
• mon casier = my locker

You do not say:

• mon le cahier ❌
• le mon cahier ❌

The possessive adjective already takes the place of an article.

Yes, that is the natural meaning.

French often uses an infinitive where English uses a clause:

• avant d’aller au café
• literally: before going to the café
• naturally in English: before I go to the café

Both express the same idea here.

Then French would usually use à un café rather than au café.

So:

• avant d’aller au café = before going to the café
• avant d’aller à un café = before going to a café

The original sentence suggests a specific café, or at least the café as a familiar place in context.