לא בא לי לפספס את האוטובוס, אז בואי נצא מוקדם.

לא בא לי is a very common colloquial Hebrew expression meaning I don’t feel like..., I’m not in the mood to..., or sometimes I don’t want to....

In this sentence, לא בא לי לפספס את האוטובוס means something like:

• I don’t feel like missing the bus
• I really don’t want to miss the bus

It is less formal and more everyday-sounding than a direct אני לא רוצה....

That is a very common learner question.

Even if the speaker is female, people usually still say בא לי, not באה לי, in this idiomatic expression.

Literally, בא לי comes from the verb לבוא (to come) and means something like it comes to me, but in modern spoken Hebrew it functions as a fixed expression.

So:

• בא לי קפה = I feel like coffee
• לא בא לי ללכת = I don’t feel like going

Treat בא לי as a set phrase in everyday Hebrew.

The ל־ marks the infinitive in Hebrew.

So:

• לפספס = to miss
• לצאת = to go out / to leave
• ללכת = to go

After expressions like בא לי or לא בא לי, Hebrew often uses an infinitive:

• בא לי לאכול = I feel like eating
• לא בא לי לעבוד = I don’t feel like working

So לא בא לי לפספס means I don’t feel like missing.

לפספס usually means to miss, to fail to catch, or to miss out on.

In this sentence, לפספס את האוטובוס means to miss the bus.

Examples:

• פספסתי את הרכבת = I missed the train
• אל תפספס את ההזדמנות = Don’t miss the opportunity

It is very common in spoken Hebrew and perfectly natural, though it has a somewhat colloquial feel. In many situations, it is the normal word people would use.

את marks a definite direct object in Hebrew.

Since האוטובוס means the bus and is definite because of ה־ (the), Hebrew uses את before it:

• לפספס את האוטובוס = to miss the bus

Compare:

• ראיתי את הסרט = I saw the movie
• קניתי את הספר = I bought the book

But if the noun is indefinite, את is usually not used:

• ראיתי סרט = I saw a movie

So here את appears because it is the bus, not just a bus.

Yes, literally בואי means come! when speaking to one female.

But in Hebrew, בוא / בואי / בואו is also commonly used to introduce a suggestion, almost like come on, let’s...

So:

• בואי נצא מוקדם = Let’s leave early
• more literally: Come, let’s leave early

It sounds very natural in spoken Hebrew.

Because the form here is בואי, the speaker is addressing one female.

It changes according to who is being addressed:

• בוא נצא מוקדם = speaking to one male
• בואי נצא מוקדם = speaking to one female
• בואו נצא מוקדם = speaking to more than one person

So the sentence as written is specifically addressed to a woman.

Hebrew often uses the first person plural future to express let’s...

So:

• נצא literally = we will go out / we will leave
• in context = let’s leave

This is very normal Hebrew usage.

More examples:

• נלך = let’s go
• נחכה = let’s wait
• נתחיל = let’s begin

So בואי נצא מוקדם is a standard way to say let’s leave early.

Both are possible meanings of לצאת, and context decides which one fits.

לצאת can mean:

• to go out
• to leave
• to head out

In this sentence, because they want to avoid missing the bus, נצא מוקדם is best understood as:

• let’s leave early
• let’s head out early

So it does not necessarily mean go out for fun here; it means leave earlier than planned.

מוקדם literally means early.

Although it is originally an adjective, Hebrew often uses words like this adverbially too, just as English does in some expressions.

So:

• נצא מוקדם = we’ll leave early / let’s leave early

You can think of מוקדם here as functioning like an adverb describing when they should leave.

It is natural, everyday spoken Hebrew.

The especially colloquial parts are:

• לא בא לי = very conversational
• בואי נצא... = very natural spoken suggestion

A more formal version might say something like:

• אני לא רוצה לפספס את האוטובוס, אז כדאי שנצא מוקדם

That sounds more neutral or formal. But the original sentence is exactly the kind of thing people commonly say in conversation.