Mi skribis motivleteron.

In Esperanto, -is marks the past tense for all verbs.

• skribi = to write
• skribas = write / am writing
• skribis = wrote
• skribos = will write

So Mi skribis means I wrote.

The -n ending marks the direct object in Esperanto. The direct object is the thing directly affected by the action.

In this sentence:

• Mi = I
• skribis = wrote
• motivleteron = a motivation letter / cover letter

The letter is what was written, so it takes -n.

Without the -n, the grammar would be incomplete or incorrect in standard Esperanto.

The basic dictionary form is motivletero.

Breakdown:

• motiv- = motive / motivation
• letero = letter
• motivletero = motivation letter

Then Esperanto adds -n because it is the direct object:

• motivletero → motivleteron

Yes. Esperanto very often forms new words by combining roots into a single word.

So:

• motivo = motive
• letero = letter
• motivletero = motivation letter

This is very normal in Esperanto. English sometimes writes similar ideas as two words, but Esperanto often joins them into one compound.

Esperanto has no indefinite article like English a/an.

So motivleteron can mean:

• a motivation letter
• sometimes just motivation letter, depending on context

Esperanto does have a definite article, la, for the. If you wanted to say the motivation letter, you would say:

• Mi skribis la motivleteron.

Normally, you should include Mi.

Even though Esperanto verb endings show tense, they do not show the person the way some languages do. For example, skribis could mean:

• I wrote
• you wrote
• he wrote
• she wrote
• we wrote
• they wrote

So the subject pronoun is usually necessary:

• Mi skribis = I wrote
• Li skribis = He wrote
• Ni skribis = We wrote

Yes, Esperanto word order is fairly flexible, especially because the -n ending shows the object clearly.

The normal order is:

• Mi skribis motivleteron.

But these are also understandable:

• Motivleteron mi skribis.
• Skribis mi motivleteron.

Still, the most natural and beginner-friendly order is subject–verb–object, just like in English.

A simple English-speaker guide:

• Mi ≈ mee
• skribis ≈ SKREE-bis
• motivleteron ≈ mo-TEEV-le-TE-ron

A few helpful pronunciation points:

• Esperanto vowels are consistent:
  • i = like ee
  • e = like eh
  • o = like oh
• Stress is always on the second-to-last syllable:
  • skri-BIS
  • motivle-TE-ron

You could, but it means something different.

• Mi skribis motivleteron. = I wrote a motivation letter.
• Mi estis skribanta motivleteron. = I was in the process of writing a motivation letter.

The original sentence is simpler and more natural if you just want to state that the writing happened in the past.

Often, yes, depending on context.

motivletero literally means motivation letter, and it is commonly used for the kind of letter sent with a job application. In many contexts, English speakers would call that a cover letter.

So the exact English translation can depend on the situation, but the Esperanto grammar of the sentence stays the same.