Ten, kto umie ratować innych, powinien też umieć spokojnie mówić przez telefon.

Ten, kto is a common Polish pattern meaning the one who.

• ten points to a person
• kto introduces the clause describing that person

So Ten, kto umie ratować innych... means something like The person who knows how to save others...

You could also say Kto umie ratować innych, powinien..., which is closer to Whoever knows how to save others should... That version is also correct, but ten, kto is a little more explicit.

In Polish, the clause introduced by kto is separated by commas in this structure:

Ten, kto ..., ...

So here:

• Ten = the main part
• kto umie ratować innych = the inserted descriptive clause
• the second comma closes that clause

This is standard punctuation in Polish.

umieć means to know how to do something, especially as a skill.

So umie ratować innych suggests real ability or training.

Compare:

• umieć = know how
• potrafić = be able to, be capable of
• móc = can, may, be able to in the sense of possibility or permission

In this sentence, umie works very well because saving others is treated as a learned skill.
potrafi ratować innych would also be possible, but it sounds a bit different in nuance.
może ratować innych would mean something more like is able to / is allowed to save others, which is not the main idea here.

This is about aspect.

• ratować is imperfective
• uratować is perfective

Here the sentence is talking about a general skill, not one completed rescue. Because of that, ratować is more natural.

• umie ratować innych = knows how to save others, in general
• umie uratować innych would sound more like knows how to bring a rescue to successful completion, which is less natural in a broad statement like this

When Polish talks about abilities or repeated/general actions, the imperfective is usually preferred.

innych here means others or more fully other people.

It is in the accusative plural, because it is the direct object of ratować.

The important point is that for masculine personal plural nouns and pronouns, the accusative often looks like the genitive. Since others here means people, you get:

• ratować innych

You can think of it as an omitted noun:

• ratować innych ludzi = save other people

If it referred to non-human things, the form would often be different.

powinien means should.

It behaves a lot like a modal verb in English and is followed by an infinitive:

• powinien umieć
• should know how to

So the structure is:

• powinien = should
• umieć = know how
• mówić = speak

Altogether: powinien też umieć spokojnie mówić przez telefon = should also know how to speak calmly on the phone.

Because they have different grammatical roles.

• umie is a conjugated verb: he/she knows how
• umieć is the infinitive: to know how

In the first part, the clause needs a normal finite verb:

• kto umie ratować innych

In the second part, powinien is followed by an infinitive:

• powinien umieć spokojnie mówić

So this change is completely normal.

No. This is often a generic masculine singular, which Polish commonly uses when talking about a person in general.

So Ten, kto... powinien... does not have to mean only a man. It can mean a person in general.

If you wanted to refer specifically to a woman, you would normally change the whole structure, for example:

• Ta, która umie ratować innych, powinna też...

That sounds more natural than trying to force a feminine version of ten, kto.

Because spokojnie is an adverb, and it describes how someone speaks.

• mówić spokojnie = to speak calmly

By contrast:

• spokojny / spokojna are adjectives
• they describe a noun, not the action

So here Polish needs the adverb spokojnie, just as English uses calmly, not calm.

Yes, literally przez often means through, but przez telefon is a normal Polish expression meaning:

• on the phone
• by phone
• over the phone

So you should learn mówić przez telefon as a set expression.

Also, przez takes the accusative. Here that is telefon, but the singular form happens to look the same as the nominative, so you do not see a change.

Both verbs are possible in some contexts, but they are not identical.

• mówić = to speak
• rozmawiać = to talk, to have a conversation

In this sentence, spokojnie mówić przez telefon focuses on the manner of speaking: calmly, clearly, under control. That makes a lot of sense in an emergency or professional context.

If you used rozmawiać, the focus would be a bit more on having a conversation rather than on controlled speech.

też means also or too.

Here it connects the second skill with the first one:

• someone who knows how to save others should also know how to speak calmly on the phone

Its position is natural because it comes before the part being added:

• powinien też umieć...

Polish word order is flexible, but moving też can slightly change what sounds emphasized.

Yes, that shorter version is possible:

• powinien też spokojnie mówić przez telefon

But the original sentence repeats umieć for a reason. It creates a clear parallel:

• umie ratować
• powinien też umieć mówić

That makes the second part sound like another important skill, not just a behavior someone should show once. So the repetition is meaningful and natural.