Čím déle jsem doma sám, tím víc se nudím.

It is the Czech way to express the pattern the more/longer ..., the more ....

So:

• Čím déle ... = the longer ...
• tím víc ... = the more ...

This is a very common Czech pattern, and it is best learned as a set expression:

• Čím X, tím Y
• The more X, the more Y

Examples:

• Čím víc čtu, tím víc rozumím. = The more I read, the more I understand.
• Čím jsem starší, tím jsem klidnější. = The older I am, the calmer I am.

They are fixed forms used in this comparative pattern.

Grammatically, they are related to the pronouns co and to, but in modern Czech, learners should mostly treat čím ..., tím ... as a fixed construction meaning:

• the more/longer ...
• the more ...

So you do not usually need to build this from scratch every time. Just remember:

• čím introduces the first comparison
• tím introduces the result in the second part

Because déle is the comparative form of dlouho.

• dlouho = long / for a long time
• déle = longer

So:

• dlouho jsem doma = I am home for a long time
• čím déle jsem doma = the longer I am home

English does the same kind of thing:

• long
• longer

Czech just uses the adverb comparative déle.

Yes. Víc and více both mean more.

In this sentence:

• tím víc se nudím = the more I get bored / the more bored I become

The difference is mostly style:

• víc = very common, natural, everyday
• více = a bit more formal or fuller

So both are possible:

• Čím déle jsem doma sám, tím víc se nudím.
• Čím déle jsem doma sám, tím více se nudím.

The version with víc sounds very natural.

Because Czech usually drops subject pronouns when the verb already shows who the subject is.

Here the verb forms already tell you it is I:

• jsem = I am
• nudím se = I am bored / I get bored

So já is unnecessary.

You could say:

• Čím déle jsem doma sám, tím víc se nudím.

Adding já would usually give emphasis or contrast:

• Čím déle jsem doma sám, tím víc se nudím já. = ...the more I get bored

That would only be used in a special context.

The verb is nudit se, which means to be bored or to get bored.

So:

• nudit = to bore someone
• nudit se = to be/get bored

Compare:

• Ten film mě nudí. = That film bores me.
• Nudím se. = I’m bored.

The se is part of the verb here, so you should learn nudit se as one unit.

In this sentence:

• tím víc se nudím = the more I get bored / the more bored I become

Because nudný means boring, not bored.

That is a very important difference:

• Jsem nudný. = I am boring.
• Nudím se. = I am bored.

So if you said jsem nudný, you would be describing yourself as a boring person, not saying that you feel bored.

You may also see:

• jsem znuděný / znuděná = I am bored

That is possible, but nudím se is the most natural everyday way to express the feeling.

Doma means at home.

It is the normal Czech word for being at home as a place/state:

• Jsem doma. = I am at home.

By contrast:

• v domě means in the house/building

So doma is much more natural here, because the idea is not specifically being inside a building, but simply being at home.

Compare:

• Jsem doma. = I’m at home.
• Jsem v domě. = I’m in the house/building.

In your sentence, doma is exactly the right choice.

Yes. Sám agrees with the speaker’s gender and number.

Here:

• sám = alone, by oneself
• masculine singular

So a male speaker says:

• Čím déle jsem doma sám, tím víc se nudím.

A female speaker would say:

• Čím déle jsem doma sama, tím víc se nudím.

Plural forms also change:

• sami = masculine personal plural
• samy = feminine / non-masculine plural

So this word must match who is alone.

Yes. Czech word order is flexible.

Both of these are possible:

• jsem doma sám
• jsem sám doma

They are very close in meaning. The difference is mostly emphasis and sentence rhythm.

In your sentence, jsem doma sám sounds natural and smooth. Putting sám at the end can make alone feel slightly more prominent.

So this is not a case of one being correct and the other wrong; it is more about what sounds most natural in context.

Because se is a clitic, a short unstressed word that tends to go near the beginning of its clause in Czech.

In a simple sentence, you often get:

• Nudím se.

But when something else comes first, the clitic usually moves forward:

• Tím víc se nudím.

Here, tím víc comes first, and then se appears before the verb.

This kind of placement is very normal in Czech and is something learners gradually get used to.

Yes. Dýl is a common colloquial form of déle.

So:

• čím déle = more standard / neutral
• čím dýl = more informal, spoken

Both are common:

• Čím déle jsem doma sám, tím víc se nudím.
• Čím dýl jsem doma sám, tím víc se nudím.

If you are aiming for standard textbook Czech, use déle. If you want natural everyday spoken Czech, dýl is also very common.

Usually it sounds like a general observation:

• The longer I’m home alone, the more bored I get.

So it describes a pattern or tendency, not necessarily only one specific event.

Czech often uses the present tense this way, just like English can:

• Čím déle čekám, tím jsem nervóznější. = The longer I wait, the more nervous I get.

So your sentence is naturally understood as a general cause-and-effect relationship.