Із стелі капає вода, бо після дощу дах ще не сухий.

Yes. із, з, and зі are all variants of the same preposition meaning from/off/out of. Ukrainian often switches between them for smoother pronunciation.

Here, із стелі sounds natural because з стелі would create a harder consonant cluster. You may also hear зі стелі in real speech. All three are related; the choice is mostly about euphony.

Also, this preposition requires the genitive case, which is why the noun is стелі, not стеля.

Because after із/з/зі, Ukrainian uses the genitive case.

The dictionary form is стеля = ceiling.
Its genitive singular form is стелі.

So:

• стеля = nominative
• із стелі = from the ceiling

This is very common in Ukrainian: prepositions often determine the case of the noun that follows.

Капає is the 3rd person singular present tense form of капати, meaning to drip.

So капає вода literally means water drips / water is dripping.

A few useful points:

• Ukrainian present tense often covers what English expresses as both drips and is dripping.
• The verb is singular because вода is singular.

Ukrainian word order is much more flexible than English word order.

Both are possible:

• Із стелі капає вода
• Вода капає зі стелі

The version in your sentence sounds very natural because it first sets the scene with із стелі, then presents what is happening: капає вода. This kind of ordering is common when describing a situation or something suddenly noticeable.

So the difference is mostly about focus and style, not basic meaning.

Yes, тому що would also work.

Both mean because, but they differ a little in tone:

• бо = shorter, very common, natural in everyday speech
• тому що = also common, slightly fuller or more explicit

So:

• ..., бо після дощу дах ще не сухий.
• ..., тому що після дощу дах ще не сухий.

Both are correct.

Because після requires the genitive case.

The noun is:

• дощ = rain

Its genitive singular form is:

• дощу

So:

• після дощу = after the rain / after rain

This is another case-governing preposition, just like із in із стелі.

In the present tense, Ukrainian usually omits the verb to be.

So English says:

• the roof is still not dry

But Ukrainian naturally says:

• дах ще не сухий

There is no need to add a present-tense є here. Using є in this kind of sentence would usually sound unnatural or emphatic.

Because the adjective must agree with the noun it describes.

Here the noun is дах = roof, which is:

• masculine
• singular

So the adjective must also be masculine singular:

• сухий = dry

Compare:

• дах сухий = the roof is dry
• стеля суха = the ceiling is dry
• вікно сухе = the window is dry

Ще here means still.

So:

• ще не сухий = still not dry

This is a very common pattern in Ukrainian:

• ще не готовий = still not ready
• ще не знаю = I still don’t know
• ще не прийшов = he still hasn’t come

Depending on context, ще can sometimes also correspond to English yet, but in this sentence still is the best match.

Because here не is simply making the adjective negative: not dry.

In predicative phrases like this, Ukrainian normally writes не separately:

• дах не сухий
• він не готовий
• це не важко

If written together, the meaning often shifts toward a more fixed lexical idea rather than simple negation. In this sentence, plain separate spelling is the normal choice.

Because this is a complex sentence with two clauses:

• Із стелі капає вода
• бо після дощу дах ще не сухий

In Ukrainian, a comma is normally used before бо when it introduces the reason clause.

So the punctuation here is standard and expected.