Až přijdu domů, dám si teplý čaj.

Here až means when, once, or as soon as in reference to a future event.

So Až přijdu domů... means When/Once I get home...

A very useful rule is:

• až = often used for a future point in time
• když = often used for when in general situations, repeated events, or past events

So in this sentence, až fits well because the speaker is talking about one future moment: first I get home, then I have tea.

Because přijdu comes from the perfective verb přijít.

In Czech, perfective verbs do not normally form the future with budu. Instead, their present-tense forms usually express future meaning.

So:

• přijdu = I will come / I will arrive
• not I come in this context

This is very common in Czech:

• udělám = I will do
• napíšu = I will write
• přijdu = I will come/arrive

So although the form looks present, the meaning is future.

Because domů expresses movement toward home, while doma expresses location at home.

Compare:

• Jdu domů. = I’m going home.
• Jsem doma. = I’m at home.

In your sentence, the speaker is talking about coming home, so motion is involved. That is why Czech uses domů.

A simple way to remember it:

• domů = to home / homeward
• doma = at home

It can be understood as either come home or arrive home.

The verb přijít often has the sense of to arrive or to come to a destination. So Až přijdu domů is very naturally understood as:

• When I get home
• When I come home
• When I arrive home

In natural English, When I get home is often the smoothest translation, but the Czech structure is completely normal.

Si is a short form of the reflexive pronoun in the dative.

In this sentence, dám si is an extremely common Czech expression meaning something like:

• I’ll have
• I’ll give myself
• I’ll take for myself

So:

• dám si čaj = I’ll have tea

It is not usually translated literally into English, but the idea is that the action is done for oneself.

You will hear this a lot with food and drinks:

• Dám si kávu. = I’ll have a coffee.
• Dám si polévku. = I’ll have soup.
• Dám si pivo. = I’ll have a beer.

So si is a very natural part of this pattern.

Because dát is perfective, and here the speaker means a single completed action in the future: once they get home, they will have a cup of tea.

So:

• dám si teplý čaj = I’ll have a warm tea / I’ll make myself a warm tea

Using budu si dávat would sound more like an ongoing, repeated, or habitual action, which does not fit this situation as well.

This is another aspect example:

• dát si = have something once, as a completed action
• dávat si = have/take something repeatedly or as a process

So dám si is the natural choice here.

Because Czech often leaves out subject pronouns when the verb ending already makes the subject clear.

Here:

• přijdu clearly means I will come
• dám clearly means I will give / I will have

So já is unnecessary.

Czech does this all the time:

• Jdu domů. = I’m going home.
• Mám hlad. = I’m hungry.
• Udělám to. = I’ll do it.

You can add já for emphasis or contrast, but in a neutral sentence it is usually omitted.

Because čaj is the direct object of dám si, so it is in the accusative case.

The noun čaj is a masculine inanimate noun, and for many masculine inanimate nouns, the accusative singular looks the same as the nominative singular.

So:

• nominative: teplý čaj
• accusative: teplý čaj

They look identical here.

The adjective teplý agrees with čaj in gender, number, and case.

So the form is exactly what you would expect for a masculine inanimate singular direct object.

Both are possible, but they do not mean exactly the same thing.

• teplý = warm
• horký = hot

So teplý čaj suggests tea that is pleasantly warm, while horký čaj suggests tea that is really hot.

In everyday speech, teplý čaj is very natural if the speaker simply means a nice warm tea. If they wanted to stress that it is steaming hot, horký čaj would be more appropriate.

Yes. Czech word order is flexible, although the choice affects emphasis and style.

The original sentence:

• Až přijdu domů, dám si teplý čaj.

is very natural and neutral: first the time clause, then the main action.

You could also say:

• Dám si teplý čaj, až přijdu domů.

That also works, but it puts the tea part first and the time clause second.

The meaning stays basically the same. Czech word order often depends on what the speaker wants to emphasize or what sounds most natural in context.

Also notice the comma: when the až clause comes first, it is separated by a comma.

By itself, it most naturally sounds like a one-time future event.

That is mainly because of the perfective verbs:

• přijdu
• dám

Perfective verbs point to single completed events. So the sentence suggests:

1. I get home.
2. Then I have warm tea.

If you wanted to talk more about a repeated habit, Czech would often use different wording, often with imperfective verbs or extra context.

So this sentence is best understood as one future occasion, not a general routine.