Mi portas kompason en la tornistro.

The -n marks the direct object in Esperanto.

In Mi portas kompason en la tornistro:

• Mi = the subject, the person doing the action
• portas = carries / is carrying
• kompason = the thing being carried

So kompaso becomes kompason because it is what the verb acts on.

A very literal breakdown is:

• Mi = I
• portas = carry
• kompason = a compass

This -n ending is one of the most important grammar markers in Esperanto.

Because en la tornistro is a prepositional phrase, not the direct object.

Here:

• kompason is the direct object, so it gets -n
• en la tornistro means in the backpack, and en already shows the relationship

So tornistro stays in its basic form.

A useful rule for beginners is:

• nouns as direct objects often take -n
• nouns after prepositions usually do not

In this sentence, the backpack is the place where the compass is.

Porti often means to carry, but it can also mean to wear, depending on context.

In this sentence, with kompason en la tornistro, the natural meaning is carry: the speaker has a compass with them, inside the backpack.

Examples:

• Mi portas sakon. = I am carrying a bag.
• Mi portas ĉapelon. = I am wearing a hat.

So porti is broader than just one English word. You choose the best English translation from the context.

Esperanto does not have a separate verb form for the English progressive like am carrying.

The ending -as simply marks the present tense.

So Mi portas can mean:

• I carry
• I am carrying

The exact English translation depends on context. Esperanto often uses one simple present form where English has more than one option.

En la tornistro tells you where the compass is.

It modifies the situation by showing location: the compass is being carried in the backpack.

So the structure is roughly:

• Mi portas = I am carrying
• kompason = a compass
• en la tornistro = in the backpack

This does not usually mean that I am in the backpack. It means the compass is in the backpack.

La is the definite article, meaning the.

Esperanto uses la when the speaker has a specific thing in mind. So en la tornistro means in the backpack.

Without la, en tornistro would sound unusual in normal Esperanto. Usually you would say either:

• en la tornistro = in the backpack
• en mia tornistro = in my backpack
• en tornistro is generally not the normal choice here

Esperanto articles are simpler than English because there is only one article, la, and no separate word for a/an.

Yes. Esperanto word order is fairly flexible because endings show the grammatical roles.

For example, these are possible:

• Mi portas kompason en la tornistro.
• En la tornistro mi portas kompason.
• Kompason mi portas en la tornistro.

They all keep basically the same meaning, because kompason still has the -n marking it as the object.

However, the most neutral and natural order is usually the original one: Mi portas kompason en la tornistro.

No, not as written.

The sentence says that the speaker carries a compass, and that the compass is in the backpack.

If you wanted to say I am wearing/carrying a backpack, you would say something like:

• Mi portas tornistron. = I am carrying/wearing a backpack.

So in your sentence, the direct object is kompason, not tornistron. That tells you the compass is the thing being carried.

Not exactly.

• Mi portas kompason en la tornistro means I am carrying a compass in the backpack. It focuses on the act of carrying it with you.
• Mi havas kompason en la tornistro means I have a compass in the backpack. It focuses more on possession or the fact that it is there.

Often the difference is small in real life, but the verbs are not identical:

• porti = carry / wear
• havi = have

So the original sentence emphasizes carrying, not just possession.