Si tu ne prends pas le premier bus, tu risques d’être en retard au travail.

Because the verb prendre has to agree with tu.

In the present tense:

• je prends
• tu prends
• il/elle/on prend
• nous prenons
• vous prenez
• ils/elles prennent

So with tu, the correct form is prends.

In standard French, negation is usually made with ne before the verb and pas after it.

So:

• tu prends = you take
• tu ne prends pas = you do not take

In everyday spoken French, people often drop ne, especially informally:

• Si tu prends pas le premier bus...

But in careful written French, ne ... pas is the normal form.

Si means if when it introduces a condition.

So:

• Si tu ne prends pas le premier bus = If you don’t take the first bus

This is a very common structure in French for conditional statements.

Be careful: this si means if, not yes. French si can also mean yes in response to a negative question, but that is a different use.

French often uses the present tense in both parts of a real or likely condition.

Pattern:

• Si + present, present / future / imperative

Here:

• Si tu ne prends pas le premier bus = If you don’t take the first bus
• tu risques d’être en retard = you risk being late / you’re likely to be late

English sometimes uses present + future, but French does not use the future tense directly after si in this kind of sentence.

So Si tu ne prendras pas... would be wrong here.

French usually needs an article before a noun.

So you say:

• le bus = the bus
• un bus = a bus
• le premier bus = the first bus

French does not usually omit the article the way English sometimes can.

Premier means first.

In French, some common adjectives come before the noun, and premier is one of them:

• le premier bus = the first bus
• la première fois = the first time

Since bus is masculine singular, the adjective is premier.
If the noun were feminine, it would become première.

The verb risquer is followed by de + infinitive when it means to risk doing something or to be likely to.

So:

• tu risques de tomber = you risk falling
• tu risques d’être en retard = you risk being late

Because être starts with a vowel, de becomes d’:

• de être → d’être

That is just normal elision in French.

Here, risquer de means something like:

• to risk
• to be in danger of
• to be likely to

So tu risques d’être en retard can be understood as:

• you risk being late
• you may end up being late
• you’re likely to be late

It suggests a possible negative consequence.

In French, the expression for to be late is être en retard.

• Je suis en retard = I am late
• Il est en retard = He is late

French does not say être tard for a person being late.

Note that tard means late in the sense of late in time:

• Il est tard = It’s late

So:

• Il est tard = the time is late
• Il est en retard = he is late

Au is the contraction of à + le.

• à le travail → au travail

So:

• au travail = at work / to work, depending on context

In this sentence, en retard au travail means late for work or late at work.

French often uses à + article with places, and contractions are required:

• à le → au
• à les → aux

Not in the same way.

• en retard au travail = late for work / late at work
• pour le travail usually means for work, because of work, or for the job

So être en retard pour le travail would sound less natural here.
The usual expression is être en retard au travail.

Tu is the informal singular word for you.

Use tu with:

• friends
• family
• children
• people you know well

Vous is used for:

• one person formally
• more than one person

So the formal or plural version would be:

• Si vous ne prenez pas le premier bus, vous risquez d’être en retard au travail.

Prends is pronounced roughly like pran in English approximation, with a nasal vowel.

Important points:

• the final -ds is normally not pronounced
• the vowel is nasal, so it does not sound like ordinary English prend

Similarly:

• prend and prends sound the same in normal speech

This is common in French: different verb forms may be spelled differently but pronounced the same.

Yes. D’être is pronounced smoothly because of elision.

Instead of saying de être, French shortens it to d’être.

That makes the phrase flow more naturally:

• tu risques d’être en retard

Also, être has a circumflex accent, but that does not usually change the pronunciation in a way beginners need to worry much about here. The key thing is recognizing that d’ is just de before a vowel.

You can understand it word by word, but a natural English translation may vary.

Word-by-word:

• Si = if
• tu = you
• ne prends pas = do not take
• le premier bus = the first bus
• tu risques = you risk / you are likely
• d’être = of being / to be
• en retard = late
• au travail = at work / for work

Natural English versions could be:

• If you don’t take the first bus, you risk being late for work.
• If you don’t catch the first bus, you might be late for work.
• If you miss the first bus, you could end up late for work.

So the French structure is clear, but the best English wording depends on style.

Yes. Prendre le bus often means to take the bus, but depending on context it can also be translated as to catch the bus.

In this sentence, English might naturally use either:

• take the first bus
• catch the first bus

If the idea is about not missing a scheduled bus, catch may sound especially natural in English, even though French still uses prendre.