Chci připojistit rizikový sport.

In Czech, the subject pronoun is often omitted because the verb ending already tells you who the subject is.

• chci = I want
• so já is not necessary

You can say Já chci připojistit rizikový sport, but that usually adds emphasis or contrast, for example:

• Já chci..., ne on. = I want to..., not him.

So the version without já is the normal neutral one.

Chci is the 1st person singular present tense form of chtít (to want).

A few common forms are:

• chci = I want
• chceš = you want
• chce = he/she/it wants
• chceme = we want
• chcete = you want
• chtějí = they want

So chci by itself already means I want.

Because after chtít Czech normally uses an infinitive, just like English uses to + verb after want.

So the structure is:

• chci + infinitive

Examples:

• Chci jít. = I want to go.
• Chci koupit pojištění. = I want to buy insurance.
• Chci připojistit rizikový sport. = I want to add insurance coverage for a risky sport.

This is a very standard pattern.

Not exactly. The basic verb pojistit means to insure.
The verb připojistit adds the idea of adding extra insurance coverage or insuring additionally.

So it often means something like:

• to add insurance for something
• to extend insurance coverage
• to include something extra in an insurance policy

That is why připojistit is common in insurance contexts.

Related noun:

• připojištění = additional insurance / supplementary coverage

Very often, yes, si sounds natural when you mean that you are arranging something for yourself.

So:

• Chci připojistit rizikový sport. = grammatical and understandable
• Chci si připojistit rizikový sport. = often more natural in everyday usage

The version with si can suggest:

• I want to add this coverage for myself
• I want to add it to my own insurance

In practical speech, especially in services like insurance, Czech often uses si in this kind of sentence.

It is in the accusative case, because it is the direct object of the verb připojistit.

You are adding insurance coverage for what?

• rizikový sport

So it is the object, and that calls for the accusative.

Good question. It looks the same because sport is masculine inanimate, and in the singular, masculine inanimate accusative is the same as the nominative.

So:

• nominative: rizikový sport
• accusative: rizikový sport

That is completely normal.

Compare that with masculine animate nouns, where the accusative usually changes:

• nominative: dobrý lékař
• accusative: dobrého lékaře

So here nothing changes because sport is inanimate.

It can depend on context.

In the singular, rizikový sport can mean:

• one specific risky sport
• a risky sport as a category, in a general or administrative sense

If you mean multiple sports, you would usually say:

• rizikové sporty

In insurance language, you may also hear:

• připojištění na rizikové sporty

That can sound more natural when talking about coverage for risky or extreme sports in general.

No, Czech word order is fairly flexible.

The neutral order here is:

• Chci připojistit rizikový sport.

But other orders are possible, depending on emphasis:

• Rizikový sport chci připojistit.
• Rizikový sport si chci připojistit.
• Chci si rizikový sport připojistit.

The basic meaning stays similar, but the focus changes.

A useful rule:

• the more neutral version usually puts the verb phrase first and the object later
• if you move rizikový sport forward, you emphasize it

Yes, chci is tricky for English speakers.

A rough guide is:

• chci ≈ kh-tsee

Notes:

• ch in Czech is like the sound in Scottish loch or German Bach
• the c is pronounced ts
• so the whole word is a tight cluster: kh-tsi

Also remember that Czech stress is usually on the first syllable:

• CHCI
• přiPOjistit? No — the main stress is still on the first syllable of the whole word: PŘIpojistit
• RIzikový
• SPORT

The sound ř in připojistit is especially difficult; it has no exact English equivalent.