Learn Hardcore Finnish: On helpompi luottaa itseensä, kun näkee, että on oppinut paljon. - It is easier to trust yourself when you see that you have learned a lot.

On helpompi luottaa itseensä ≈ It is easier to trust oneself.
There is no explicit subject; the whole infinitive phrase luottaa itseensä is what’s being talked about.

About helpompi vs. helpompaa:

On helpompi luottaa… (nominative) – very common, perfectly correct.
On helpompaa luottaa… (partitive) – also correct; can sound a bit more “abstract”, like “it is easier (in some respect) to trust…”.

Both are fine here; the choice is mostly stylistic. Using se (Se on helpompi…) would sound less natural in this kind of generic statement.

What exactly is helpompi and how does it work in this sentence?

helpompi is the comparative form of the adjective helppo (easy):

helppo – easy
helpompi – easier
helpoin – easiest

Here it’s a predicative adjective linked to an implied subject:

(Se / Tämä) on helpompi (asia) – (It / This) is easier (thing).

But since Finnish allows subjectless on + adjective structures, you get:

On helpompi luottaa itseensä – It is easier to trust oneself.

So helpompi describes the “degree of ease” of the action luottaa itseensä.

Why is luottaa in the basic (infinitive) form and not luotan or luotat?

luottaa is the 1st infinitive, used like English to trust after adjectives such as helppo, vaikea, mahdotonta, etc.

Pattern:

On helppo ymmärtää. – It is easy to understand.
On vaikea selittää. – It is hard to explain.
On helpompi luottaa. – It is easier to trust.

If you used a personal form like luotan (I trust), the sentence would need a completely different structure:

Luotan itseeni enemmän, kun näen, että olen oppinut paljon.
I trust myself more when I see that I have learned a lot.

In the original sentence, the idea is more general and impersonal, so the infinitive is natural.

Why is it itseensä and not something like itseesi or itseeni? What form is this?

itseensä is the reflexive pronoun in the illative case (the “into / to” case):

base: itse – self
3rd person reflexive (oneself): itsensä
illative of itsensä: itseensä – into / to oneself

So luottaa itseensä literally means to trust into oneself, i.e. to trust oneself / have confidence in oneself.

You’d use personal forms if you had an explicit subject:

Luotan itseeni. – I trust myself.
Luotat itseesi. – You (sg) trust yourself.
Hän luottaa itseensä. – He / she trusts him/herself.

In generic, impersonal statements Finnish normally uses the 3rd person reflexive (itseensä), even when English says yourself or oneself.

In kun näkee, who is actually “seeing”? Why is it third person singular?

näkee is 3rd person singular of nähdä (to see), but here it’s used generically:

kun näkee ≈ when one sees / when you see / when people see

Finnish often expresses generic “you/one” with:

3rd person singular (as here): kun näkee, jos ajattelee
or passive: kun nähdään, jos ajatellaan

So there is no explicit subject; it’s understood to refer to people in general, including the speaker and listener.

Why is there a comma before kun and before että?

Finnish comma rules are stricter than English ones.

You normally put a comma before a subordinate clause introduced by words like kun (when) or että (that):

On helpompi luottaa itseensä, kun näkee…
…kun näkee, että on oppinut paljon.

So:

main clause: On helpompi luottaa itseensä
subordinate clause 1: kun näkee
subordinate clause 2 (inside 1): että on oppinut paljon

Each subordinate clause is separated with a comma from what comes before it.

In että on oppinut paljon, who is the subject of on oppinut and why is there no pronoun like hän or olemme?

Again, this is the same generic 3rd person as in näkee.

että on oppinut paljon ≈ that one has learned a lot / that you have learned a lot.

The subject is understood, not pronounced. Finnish can omit pronouns when the reference is clear from context or when the meaning is generic.

If you made it personal, you would add the pronoun and change the verb form:

että olen oppinut paljon – that I have learned a lot
että olet oppinut paljon – that you (sg) have learned a lot
että hän on oppinut paljon – that he/she has learned a lot

The original sentence intentionally keeps things impersonal and general.

Why is the tense on oppinut (has learned) instead of oppi (learned)?

on oppinut is the present perfect (auxiliary olla + past participle):

oppia – to learn
oppi – learned (simple past)
on oppinut – has learned (present perfect)

The present perfect is used to show a result that is still relevant now:

että on oppinut paljon – that one has learned a lot (and still knows it now).

If you said että oppi paljon, it would sound more like a finished past event, without emphasizing the ongoing result. In this context, the idea is “seeing that you have already learned a lot and that knowledge is still with you now,” so on oppinut fits well.

What is the role of paljon here, and could it be paljoa?

paljon means a lot / much and here it modifies the verb oppinut:

on oppinut paljon – has learned a lot.

Sometimes you’ll also see paljoa, which is the partitive form. The difference:

paljon – neutral and very common in spoken and written Finnish.
paljoa – more clearly partitive, often in negative clauses or slightly more formal style.

Here, on oppinut paljon is the natural choice. on oppinut paljoa is grammatically possible but sounds more marked or old-fashioned in everyday language.

Can I change the word order, for example: Kun näkee, että on oppinut paljon, on helpompi luottaa itseensä?

Yes, that word order is very natural, and many speakers might even prefer it:

Kun näkee, että on oppinut paljon, on helpompi luottaa itseensä.

Finnish allows relatively free word order, especially with clauses. Moving the kun-clause to the front just changes the rhythm and emphasis slightly:

original: start with the general statement On helpompi luottaa itseensä, then explain kun…
reordered: first set the condition Kun näkee, että on oppinut paljon, then state the result on helpompi luottaa itseensä.

Both versions are correct and mean the same thing.