Learn Hardcore Esperanto: Mia horloĝo ofte malfruas, sed ĝia laŭta bruo tamen vekas min. - My clock is often slow, but its loud noise still wakes me.

Both are understandable, but malfrui is the normal, idiomatic verb used for being late in Esperanto. Using malfrui treats “being late” as an action/state in itself, not just a quality.

How is malfruas built from smaller parts?

You can break malfruas down like this:

fru- = root meaning early
mal- = prefix meaning the opposite
malfru- = late
-i (infinitive) → malfrui = to be late
-as (present tense) → malfruas = is late / is running late

So Mia horloĝo ofte malfruas literally:
My clock often is-late (i.e. it often runs slow or shows a time that is too late).

Why is it ofte malfruas instead of malfruas ofte? Does word order matter?

Both orders are grammatically correct:

Mia horloĝo ofte malfruas
Mia horloĝo malfruas ofte

In Esperanto, adverbs like ofte (often) are quite free in their position. The most common is before the verb, as in the original sentence. Putting ofte after the verb can give it a bit more emphasis, but the difference is subtle.

So you can safely say either; the original is just the more typical order.

Why is there no la in Mia horloĝo? In English we say “my clock”, not “the my clock”.

In Esperanto, a possessive pronoun like mia usually replaces the definite article la:

la horloĝo = the clock
mia horloĝo = my clock (not la mia horloĝo)

You normally do not say la mia horloĝo. La can appear before a possessive only in special cases, usually when the possessive stands alone as a noun, e.g.:

la mia = mine
la via = yours

But in mia horloĝo, mia is just an adjective describing horloĝo, so no la is needed.

Why do we have both sed and tamen? Aren’t they both like “but / however”?

They are related, but not identical:

sed = but (introduces a contrast)
tamen = however / nevertheless / still (adds the idea “even so”)

In … sed ĝia laŭta bruo tamen vekas min:

sed contrasts “my clock is often late” with “it wakes me up”
tamen emphasizes that this happens in spite of the first fact.

You could say:

Mia horloĝo ofte malfruas, sed ĝia laŭta bruo vekas min.
Mia horloĝo ofte malfruas, tamen ĝia laŭta bruo vekas min.

Both are fine. Using both sed and tamen is very natural and gives the nuance “but even so / but still”.

Could I move tamen somewhere else, like … tamen ĝia laŭta bruo vekas min or … ĝia laŭta bruo vekas tamen min?

Yes, tamen (like many adverbs) can move around in the clause. The most usual places are:

Sed tamen ĝia laŭta bruo vekas min.
Sed ĝia laŭta bruo tamen vekas min. ← very natural
Sed ĝia laŭta bruo vekas tamen min. (correct, but a bit marked/emphatic)

Changing the position can subtly change emphasis, but it does not change the basic meaning. The original … ĝia laŭta bruo tamen vekas min is completely standard and clear.

Why is it ĝia and not sia in sed ĝia laŭta bruo tamen vekas min?

This is a classic reflexive-pronoun question.

Key rule: sia (reflexive) refers back to the subject of the clause and is normally not used inside the subject phrase itself.

In the second half:

Subject of the verb vekas is ĝia laŭta bruo (its loud noise)
The owner of that noise is ĝi (implied: mia horloĝo)

So:

ĝia laŭta bruo = the loud noise of it (the clock)

If we tried sia laŭta bruo:

sia would have to refer to the subject of the clause
but sia laŭta bruo itself is the subject
that gives the weird idea “its own loud noise’s loud noise wakes me”, and it breaks the normal rule that sia is not used as part of the subject noun phrase.

Therefore ĝia is correct here, not sia.

Why is ĝia used at all? Does ĝi refer to things like clocks?

Yes. In Esperanto:

li = he (male person)
ŝi = she (female person)
ili = they
ĝi = it (things, animals, or a person when sex is unknown or irrelevant)

A clock is an inanimate object, so ĝi is the natural pronoun. Then:

ĝia = its (possessive form of ĝi)

So ĝia laŭta bruo = its loud noise, referring to mia horloĝo from the first clause.

Why laŭta bruo and not something like laŭte bruo?

Because laŭta is an adjective and must agree with the noun:

laŭta = loud (adjective, describing a noun)
laŭte = loudly (adverb, describing a verb, adjective, or another adverb)
bruo = noise

So:

laŭta bruo = loud noise (correct)
laŭte bruo would be mixing adverb + noun, which is wrong.

If you wanted an adverb, it would modify a verb:

La horloĝo bruas laŭte. = The clock makes noise loudly.

What is the difference between bruo and sono? Could I say laŭta sono instead?

Both are about sounds, but with different nuance:

sono = sound (neutral, can be pleasant or neutral)
- bela sono = a beautiful sound
- mola sono = a soft sound
bruo = noise (often loud, disturbing, irregular)
- forta bruo = a strong/violent noise
- strata bruo = street noise

In the sentence, laŭta bruo suggests an annoying, loud noise, which fits well with a clock that wakes you up.
You could say laŭta sono, but that sounds a bit more neutral and less “noisy”.

Why do we say vekas min with min in the accusative?

Veki is a transitive verb: it takes a direct object.

veki iun = to wake someone (up)

In Esperanto, the direct object is marked with -n (the accusative ending). So:

ĝi vekas min = it wakes me (up)
ĝi vekas min ĉiumatene = it wakes me every morning

Without -n, mi would be a subject form, which would change the structure and make the sentence wrong or confusing. So min here is required.

Could I also say La laŭta bruo de mia horloĝo tamen vekas min? Is that equivalent?

Yes, that is a good and natural alternative:

La laŭta bruo de mia horloĝo tamen vekas min.
= The loud noise of my clock still wakes me.

Compared to sed ĝia laŭta bruo tamen vekas min:

ĝia connects more tightly back to mia horloĝo in the previous clause, keeping the sentence compact.
de mia horloĝo is a bit more explicit and independent; it doesn’t rely on ĝia referring back to something.

Both are grammatically correct; the original just splits the information into two clauses and uses a pronoun, which is very typical style in Esperanto.