Sypię cukier do kawy, bo jest zbyt gorzka.

In Polish, subject pronouns are often omitted because the verb ending already shows who is doing the action.

• sypię = I pour / I am adding / I sprinkle
• The ending -ę tells you it is 1st person singular: I

So Sypię cukier do kawy already means I’m adding sugar to the coffee.
You could say Ja sypię cukier do kawy, but ja would usually add emphasis, like I’m the one adding sugar.

It can mean both, depending on context.

Polish present tense often covers both:

• I pour
• I am pouring

Because sypię is an imperfective verb form, it can describe:

• an action happening right now
• a repeated/habitual action

So this sentence could mean either:

• I’m adding sugar to the coffee because it’s too bitter
• I add sugar to coffee because it’s too bitter

Context tells you which one is meant.

Sypać is used for loose, granular substances such as:

• cukier (sugar)
• sól (salt)
• mąka (flour)
• piasek (sand)

So sypię cukier is natural because sugar is something you pour/sprinkle.

You could also say daję cukier do kawy = I put/add sugar in the coffee, and that is understandable and natural too. But sypię is more specific and vividly matches the physical action of adding granules.

Because cukier is a masculine inanimate noun, and in the singular its accusative form is usually the same as its nominative form.

Here cukier is the direct object of sypię, so it is in the accusative case. But it looks the same as the dictionary form:

• nominative: cukier
• accusative: cukier

This is very common with masculine inanimate nouns in Polish.

Kawy is in the genitive singular.

The preposition do usually requires the genitive case.
The noun changes like this:

• nominative: kawa
• genitive: kawy

So:

• do kawy = to/into the coffee

In Polish, this is a normal way to talk about adding something to a drink or food:

• cukier do kawy
• cytryna do herbaty
• sól do zupy

Polish often leaves out possessive words like my, your, his, etc. when the meaning is obvious from context.

So do kawy can naturally mean:

• to the coffee
• to my coffee

If you wanted to make it explicit, you could say:

• do mojej kawy = to my coffee

But in everyday Polish, that extra word is often unnecessary.

Bo means because.

It is very common in everyday speech and sounds natural here:

• Sypię cukier do kawy, bo jest zbyt gorzka.

You could also use ponieważ, which also means because, but it is usually a bit more formal or written in style:

• Sypię cukier do kawy, ponieważ jest zbyt gorzka.

Both are correct. Bo is the more conversational choice.

Because the adjective agrees with kawa, which is a feminine singular noun.

• kawa = feminine
• therefore gorzka = feminine singular form of bitter

So the full idea is:

• bo kawa jest zbyt gorzka = because the coffee is too bitter

Polish often omits repeated nouns when they are obvious, so kawa is understood and not repeated.

If the noun were masculine, you would use gorzki.
For example:

• Napój jest gorzki = The drink is bitter

The hidden subject is kawa.

Polish often omits words that are clear from context. In this sentence, the second clause does not repeat kawa, but it is understood:

• bo (kawa) jest zbyt gorzka

This is very natural in Polish. English usually prefers to repeat or replace the noun with a pronoun, but Polish can simply leave it out if the meaning is obvious.

Zbyt means too or excessively.

So:

• zbyt gorzka = too bitter

It is similar to za, and in everyday speech many speakers would probably say:

• za gorzka

Both are correct, but there is a small difference in feel:

• za = very common, everyday, conversational
• zbyt = slightly more formal or careful in tone

So this sentence is correct, but bo jest za gorzka would also be very natural.

Polish word order is fairly flexible, although some orders sound more natural than others.

The original sentence is natural:

• Sypię cukier do kawy, bo jest zbyt gorzka.

You could also hear variations such as:

• Do kawy sypię cukier, bo jest zbyt gorzka.
• Bo jest zbyt gorzka, sypię cukier do kawy.

These versions change the emphasis:

• starting with Do kawy emphasizes the coffee
• starting with Bo jest zbyt gorzka emphasizes the reason

So the order can change, but the original sentence is a very normal neutral way to say it.