Mi faras la taskon kun amiko.

In Esperanto, the verb ending -as marks the present tense.

So fari = to do / to make (dictionary form)
mi faras = I do / I am doing

There is no difference between I do and I am doing in Esperanto; both are expressed with mi faras. Context usually makes it clear which English form fits best.

The ending -n shows the accusative case, mainly used for the direct object of a verb.

• Mi faras la taskon. – la taskon is the direct object (the thing being done), so it gets -n.
• kun amiko – amiko follows the preposition kun (with), so it does not take -n here.

General rule:

• Direct object of the verb → add -n (accusative): taskon, libron, amikinon.
• Noun after a normal preposition (like kun, en, sur, por) → usually no -n: kun amiko, en domo, por vi (unless you are marking direction with certain prepositions, which is a more advanced topic).

Esperanto has only one article: la, which corresponds to English the.

• la taskon = the task (a specific, known task)
• amiko without la usually means a friend or (some) friend in general, not a particular one the listener already has in mind.

So:

• Mi faras la taskon kun amiko.
  → I am doing *the task with a friend.*

If you said kun la amiko, it would sound like with the friend – some specific friend that both speaker and listener know about.

Yes, Mi faras taskon is correct, but the meaning shifts:

• Mi faras la taskon.
  → I am doing the task (a particular task that we both know about).
• Mi faras taskon.
  → I am doing a task / some task (not specified which one; just one of possibly many).

So adding la makes it specific, just like English the.

You would use the possessive adjective mia and still add the -n for the direct object:

• Mi faras mian taskon kun amiko.
  = I am doing my task with a friend.

Notice two things:

1. mia agrees with tasko and becomes mian in the accusative:

   • mia tasko (subject form)
   • mian taskon (direct object)

2. Because mia already shows whose task it is, you usually do not use la:

   • Common: mian taskon
   • la mian taskon is almost never used and sounds wrong in most contexts.

Yes. Esperanto word order is quite flexible, because the roles of words are shown by endings (like -n and -j) rather than strict position.

All of these are grammatically correct:

• Mi faras la taskon kun amiko. (neutral order)
• Kun amiko mi faras la taskon. (slight emphasis on with a friend)
• La taskon mi faras kun amiko. (emphasis on the task as opposed to something else)

As long as:

• the subject (here: mi) is clear,
• the direct object has -n (here: taskon), the sentence will be understandable.

For beginners, it is safest to stick to the neutral SVO order: Mi faras la taskon kun amiko.

No grammatical difference. Both are normally expressed by:

• Mi faras la taskon.

Esperanto verbs do not distinguish simple vs. continuous aspect like English does. The same -as ending covers both I do and I am doing. Context (or extra words like nun = now, kutime = usually) will show the nuance:

• Mi nun faras la taskon. – I am doing the task now.
• Mi ofte faras la taskon vespere. – I often do the task in the evening.

Normally, nouns after prepositions in Esperanto do not take the accusative -n, because the preposition already shows their role.

• kun amiko – with a friend (no -n needed)
• por amiko – for a friend
• en domo – in a house

The accusative -n can sometimes be added after certain prepositions to show direction / movement toward something (e.g. en la domon = into the house), but kun does not express movement, so you just use kun amiko.

In modern Esperanto, amiko generally means friend without specifying gender.

If you want to indicate gender explicitly:

• amikino – a female friend (root amik-
  • feminine suffix -in-
    • -o)
• vira amiko – a male friend (literally: a male friend)

So in Mi faras la taskon kun amiko, you are simply saying with a friend, without telling the gender, unless context makes it clear.

Yes, depending on the nuance you want:

• Mi faras la taskon kun amiko.
  – I do the task with a friend. (neutral, general)

• Mi laboras pri la tasko kun amiko.
  – I work on the task with a friend. (labori pri is “to work on something”.)

• Mi plenumas la taskon kun amiko.
  – I carry out / complete the task with a friend. (emphasis on fulfilling/finishing it)

Fari is the most general word for do / make, so it is very common and completely natural in the original sentence.

Normally, no. In Esperanto you almost always need to state the subject explicitly.

• Mi faras la taskon kun amiko. – correct.
• Faras la taskon kun amiko. – sounds incomplete; we do not know who is doing it.

The main regular exception is in imperatives/commands, where the subject vi (you) is often understood:

• Faru la taskon! – Do the task!

But in normal statements, you keep mi, vi, li, etc.

To make nouns plural in Esperanto, you add -j. If a noun is also in the accusative, it becomes -jn.

So:

• la tasko → la taskoj (the tasks)
• la taskon → la taskojn (the tasks as direct object)
• amiko → amikoj (friends)

Your plural sentence:

• Mi faras la taskojn kun amikoj.
  = I do the tasks with friends.

Notice:

• taskojn has -ojn (plural + accusative), because it is the direct object.
• amikoj has -oj (plural), but no -n, because it follows the preposition kun.