Mi ne malpakis ĝin ĝis mi kontrolis la mendnumeron.

Yes. Malpakis means unpacked.

It is built from:

• paki = to pack
• mal- = the opposite of
• malpaki = to unpack
• malpakis = unpacked / did unpack

So Esperanto often makes opposites with the prefix mal- instead of using a completely different root.

No. Mal- is not the same as ne.

• mal- creates an opposite meaning as part of the word
• ne negates the whole verb or sentence

So:

• mi malpakis ĝin = I unpacked it
• mi ne malpakis ĝin = I did not unpack it

This is not a double negative. Malpaki is just the normal verb to unpack, and ne says that action did not happen.

Ĝin means it.

It has -n because it is the direct object of the verb malpakis.

Breakdown:

• ĝi = it
• ĝin = it (as a direct object)

In Esperanto, direct objects usually take -n. So in Mi ne malpakis ĝin, the thing that was not unpacked is marked with -n.

Yes, here ĝis means until.

In this sentence:

• Mi ne malpakis ĝin ĝis mi kontrolis la mendnumeron.
• I didn’t unpack it until I checked the order number.

So ĝis marks the point in time up to which the first action did not happen.

A useful way to feel it is:

• before checking the order number → I did not unpack it
• after checking the order number → then I unpacked it

Because Esperanto usually uses the simple past -is for past actions, even when English might sometimes use a more complicated tense system.

Here:

• malpakis = unpacked / did unpack
• kontrolis = checked

The relationship between the actions is understood from ĝis:

• first, I checked the order number
• then, I unpacked it

Esperanto normally does not need a special past perfect form here. The timing is clear from the sentence structure.

Mendnumeron means order number.

It is a compound word:

• mendo = order
• numero = number
• mendnumero = order number
• mendnumeron = order number (direct object)

Esperanto often combines roots into one word. Usually the main idea comes at the end, so mendnumero is literally something like order-number.

The final -n appears because it is the direct object of kontrolis.

La means the.

It is used because the speaker has a specific order number in mind—the one connected with that item or purchase. So:

• kontrolis la mendnumeron = checked the order number

In real usage, this sounds natural because it is not just any order number, but the relevant one.

Yes. Esperanto word order is fairly flexible as long as the grammar remains clear.

For example, you could also say:

• Ĝis mi kontrolis la mendnumeron, mi ne malpakis ĝin.

This still means essentially the same thing: Until I checked the order number, I didn’t unpack it.

The original version is probably the most direct and natural for many learners:

• Mi ne malpakis ĝin ĝis mi kontrolis la mendnumeron.

Yes. Both are understandable.

• mendnumero = order number
• numero de la mendo = number of the order

The compound mendnumero is shorter and very natural in Esperanto, but the de phrase is also grammatical and clear.

Esperanto often prefers compact compound nouns when the meaning is straightforward.

Yes, that is the normal implication.

Mi ne malpakis ĝin ĝis mi kontrolis la mendnumeron usually means:

• I held off on unpacking it
• I checked the order number
• only then did I unpack it

So even though the sentence directly says what did not happen before the checking, it strongly suggests that the unpacking happened afterward.