Li finfine povas fleksi la genuon.

Finfine means finally, at last, or in the end.

In this sentence, it suggests that bending the knee was impossible, difficult, or delayed before, and now it has become possible.

So Li finfine povas fleksi la genuon has the feeling of:

• he can finally bend the knee
• after some time or trouble, he is now able to do it

Because Esperanto infinitives already include that meaning in the -i ending.

• fleksi = to bend
• povi = to be able to / can

So Esperanto does not need a separate word like English to here.

Because it follows povas, and after povi you normally use an infinitive.

• Li povas = He can
• fleksi = to bend

So:

• Li povas fleksi = He can bend

Only povas is conjugated for the subject. The second verb stays in the infinitive.

The -n marks the direct object.

Here, fleksi is a transitive verb: you bend something.
What is being bent? la genuo → la genuon

So:

• genuo = knee
• genuon = knee, as the direct object

You can think of it as:

• Li fleksiĝas = He bends / becomes bent
• Li fleksas la genuon = He bends the knee

In Esperanto, with body parts, it is very common to use la when the owner is obvious from the context.

So Li ... fleksi la genuon naturally means He bends his knee.

Using sian genuon is also possible, but it sounds more explicit or contrastive, as if you want to stress his own knee rather than someone else’s.

Compare:

• Li levis la manon. = He raised his hand.
• Li levis sian manon. = He raised his own hand.
  (more explicitly stated)

Yes, very often.

Esperanto commonly uses la with body parts, clothing, and similar things when the possessor is clear.

Examples:

• Ŝi fermis la okulojn. = She closed her eyes.
• Li lavis la manojn. = He washed his hands.
• Mi vundis la piedon. = I injured my foot.

This is one place where Esperanto often sounds a little different from English.

Yes. Esperanto word order is fairly flexible.

This sentence could also appear as:

• Li povas finfine fleksi la genuon.
• Finfine li povas fleksi la genuon.

All of these are grammatical. The difference is mainly emphasis or style.

The original Li finfine povas fleksi la genuon puts finfine in a natural position before povas, emphasizing finally can.

It breaks down like this:

• genu- = the root meaning knee
• -o = noun ending
• -n = accusative ending

So:

• genuo = knee
• genuon = knee as a direct object

This kind of stacking is very normal in Esperanto.

Usually, yes. Fleksi is normally transitive, meaning you bend something.

So:

• fleksi la genuon = bend the knee
• fleksi la brakon = bend the arm

If you want an intransitive or passive-like idea, Esperanto often uses -iĝi or a different phrasing, depending on context.

In this sentence, the straightforward idea is that he is able to bend the knee as a body part.

In theory, la genuon literally means the knee, but in normal context this sentence will usually be understood as his knee, because:

• the subject is li
• body parts often use la
• there is no other obvious owner mentioned

So the natural reading is He can finally bend his knee.