Mi zorge metas la pasporton en la valizon antaŭ la vojaĝo.

In Esperanto, words ending in -e are usually adverbs. Adverbs describe how something is done.

So:

• zorga = careful
• zorge = carefully

Here zorge tells you how the action is done: the passport is being put into the suitcase carefully.

Metas comes from the verb meti, meaning to put, to place, or to set.

The ending -as marks the present tense in Esperanto. So metas means something like:

• put
• am putting
• do put

Which English version sounds best depends on context. Esperanto present tense often covers both the English simple present and present progressive.

Examples:

• Mi metas la libron sur la tablon. = I put / I am putting the book on the table.
• Mi metis... = I put / I was putting... in the past
• Mi metos... = I will put... in the future

The -n marks the direct object in Esperanto.

The direct object is the thing directly affected by the verb. In this sentence, the thing being put is the passport, so it gets -n:

• pasporto = passport
• pasporton = passport as the direct object

This is called the accusative ending.

This is a very common and important Esperanto pattern.

With en:

• en + no -n usually means in or inside a place
• en + -n usually means into a place, showing movement toward the inside

So:

• en la valizo = in the suitcase
• en la valizon = into the suitcase

Because the action is one of movement or direction—putting the passport into the suitcase—Esperanto uses en la valizon.

Because here antaŭ is just a normal preposition meaning before, and the phrase is not showing motion into a place.

So:

• antaŭ la vojaĝo = before the trip

In Esperanto, nouns after prepositions normally do not take -n, unless there is a special reason such as direction or certain time/measure uses.

That is why:

• en la valizon has -n because it shows movement into something
• antaŭ la vojaĝo does not have -n because it simply gives a time relation

La is the Esperanto word for the.

Esperanto has:

• la = the
• no separate word for a or an

So:

• la pasporto = the passport
• pasporto = a passport / passport, depending on context

In this sentence, la suggests that we are talking about specific things: a particular passport and a particular suitcase.

Yes, Esperanto word order is more flexible than English word order, mainly because the -n ending helps show what the direct object is.

The neutral order here is:

• Mi = subject
• zorge = adverb
• metas = verb
• la pasporton = object
• en la valizon = direction/place phrase
• antaŭ la vojaĝo = time phrase

But other orders are possible, for example to change emphasis:

• Zorge mi metas la pasporton en la valizon antaŭ la vojaĝo.
• La pasporton mi zorge metas en la valizon antaŭ la vojaĝo.

Even so, the original version sounds natural and straightforward.

Not with exactly the same meaning.

• antaŭe = before, earlier, beforehand
• antaŭ la vojaĝo = before the trip

So antaŭe is more general, while antaŭ la vojaĝo tells you specifically before what.

Compare:

• Mi metas la pasporton en la valizon antaŭe. = I put the passport into the suitcase beforehand / earlier.
• Mi metas la pasporton en la valizon antaŭ la vojaĝo. = I put the passport into the suitcase before the trip.

You can think of antaŭe as an adverb, and antaŭ la vojaĝo as a prepositional phrase.

Esperanto pronunciation is very regular.

A rough pronunciation guide for the whole sentence is:

mee ZOR-geh MEH-tahs lah pahs-POR-tohn en lah vah-LEE-zohn AN-tow lah voh-YAH-zho

A few important points:

• j sounds like y in yes
• ĝ sounds like j in judge
• aŭ sounds roughly like ow in now
• stress is usually on the second-to-last syllable

So:

• vojaĝo is pronounced roughly voh-YAH-zho
• antaŭ is roughly AN-tow
• zorge has a hard g, like in get

In Esperanto, nouns normally end in -o in their basic form.

Here the dictionary forms are:

• pasporto = passport
• valizo = suitcase
• vojaĝo = trip, journey, voyage

Then grammar endings are added as needed:

• pasporto → pasporton because it is the direct object
• valizo → valizon because en here shows movement into
• vojaĝo stays vojaĝo because it is just the object of the preposition antaŭ

This is one reason Esperanto grammar is often considered very regular.