Mi volis veni antaŭe, sed la aŭtobuso malfruis.

Because after voli (to want), the next verb stays in the infinitive form.

• volis = wanted
• veni = to come

So Mi volis veni literally means I wanted to come.

In Esperanto, only the main verb is conjugated for tense here:

• Mi volas veni = I want to come
• Mi volis veni = I wanted to come
• Mi volos veni = I will want to come

Using venis would mean came, which would incorrectly give something like I wanted came.

The ending -is marks the past tense in Esperanto.

So:

• volas = want / am wanting
• volis = wanted
• volos = will want

In this sentence, the speaker is talking about a past situation, so volis is used.

Antaŭe is an adverb meaning before, earlier, or previously, depending on context.

In this sentence, it means something like earlier or sooner than I did. So Mi volis veni antaŭe means I wanted to come earlier.

It comes from antaŭ, which is related to the idea of before/in front of, plus the adverb ending -e.

This is a very common question.

• antaŭ is usually a preposition meaning before or in front of
• antaŭe is an adverb meaning beforehand, earlier, or previously

Examples:

• antaŭ la domo = in front of the house
• antaŭ la kunveno = before the meeting
• Mi alvenis antaŭe = I arrived earlier / beforehand

In your sentence, there is no noun after it, so the adverb antaŭe is the right form.

Because there is no direct object here.

Let’s look at the parts:

• Mi is the subject of volis
• veni is an infinitive, not a noun receiving an action
• la aŭtobuso is the subject of malfruis

The accusative -n is used mainly for direct objects and sometimes for motion toward something. Neither is happening here.

So:

• Mi volis veni = I wanted to come
• la aŭtobuso malfruis = the bus was late

No direct object, so no -n.

La means the.

So la aŭtobuso = the bus.

Using la suggests a specific bus, probably the one the speaker was planning to take. In many situations, that sounds natural.

You could sometimes omit la in Esperanto when speaking more generally, but in a sentence like this, the bus is the most natural idea.

Yes. Malfruis is the past tense of malfrui, which means to be late.

Breakdown:

• frua = early
• malfrua = late
• malfrui = to be late
• malfruis = was late

So la aŭtobuso malfruis means the bus was late.

Esperanto often turns ideas that English expresses with to be + adjective into a simple verb:

• La buso malfruis = The bus was late
• Mi malsatis = I was hungry
• Li pravis = He was right

That said, Esperanto can also use esti + adjective in some contexts, but malfrui is very common and natural.

Mal- is a very useful Esperanto prefix meaning the opposite of.

So:

• frua = early
• malfrua = late

From that you also get:

• frue = early
• malfrue = late
• malfrui = to be late

This prefix is extremely common in Esperanto and helps build opposites efficiently.

A few more examples:

• bona = good → malbona = bad
• granda = big → malgranda = small
• dekstre = right → maldekstre = left

Often, yes.

• antaŭe can mean earlier / beforehand
• pli frue more literally means earlier

In many contexts, Mi volis veni pli frue may sound especially clear to an English speaker learning Esperanto.

However, antaŭe is also understandable and natural in the sense of earlier / before that time. The exact nuance depends on context.

Very roughly:

• antaŭe = before, beforehand, earlier
• pli frue = earlier, sooner

Because Esperanto often prefers a direct verb when one exists.

• malfrui = to be late
• estis malfrua = was late / was a late one

Both can be understood, but la aŭtobuso malfruis is more idiomatic for the bus was late.

Using the verb is simpler and more natural here.

Sed means but.

It links two contrasting ideas:

• Mi volis veni antaŭe = I wanted to come earlier
• sed la aŭtobuso malfruis = but the bus was late

Its position works much like English but: it usually comes between the two clauses it connects.

Esperanto word order is fairly flexible, but this sentence uses the most neutral order.

Standard order here:

• Mi volis veni antaŭe, sed la aŭtobuso malfruis.

You could move parts around for emphasis, for example:

• Antaŭe mi volis veni, sed la aŭtobuso malfruis.

That might emphasize earlier more strongly.

Still, for learners, the original order is the safest and most natural.

The combination aŭ is a diphthong, roughly like the ow sound in English cow.

So:

• aŭtobuso sounds roughly like ow-toh-BOO-so
• antaŭe sounds roughly like ahn-TAH-weh, with aŭ giving an ow-like sound before the final -e

A few helpful reminders:

• ŭ is a special Esperanto letter
• it usually appears in combinations like aŭ and eŭ
• stress in Esperanto normally falls on the second-to-last syllable

So:

• aŭ-to-BU-so
• an-TAŬ-e

Yes, very often it does.

Mi volis veni antaŭe means I wanted to come earlier, but it does not say that the speaker succeeded. In fact, the second part of the sentence explains why not:

• sed la aŭtobuso malfruis = but the bus was late

So the full sentence naturally suggests:

• the speaker intended to come earlier
• the late bus prevented that plan

This is similar to English, where I wanted to come earlier, but... usually implies the plan failed.