Learn Hardcore Polish: W restauracji kelner szybko przynosi słodką herbatę. - In the restaurant the waiter quickly brings the sweet tea.

The preposition w means in when indicating a static location. It requires the noun that follows to be in the locative case. The base form restauracja (nominative) becomes restauracji in the locative singular.

Why is kelner in the nominative case, and what role does it play in the sentence?

kelner is the subject of the sentence—the one performing the action (“brings”). In Polish, subjects appear in the nominative case, so we keep the base form kelner.

Why isn’t there an explicit pronoun like on (he) before przynosi?

Polish often omits subject pronouns because the verb ending already indicates the person and number. Here, -i on przynosi tells you it’s 3rd person singular, so on is unnecessary.

What part of speech is szybko, and why is it placed before przynosi?

szybko is an adverb describing the manner of the action (“quickly”). Polish word order is relatively flexible, but placing an adverb directly before the verb is a common way to modify it clearly.

Why is the verb przynosi in the imperfective aspect, and how would a perfective form change the meaning?

przynosi is the imperfective form, which presents the action as ongoing or habitual. The perfective equivalent przyniesie would focus on a single, completed event—“he will bring” or “he brought (once).”

Why does słodka change to słodką, and why is herbata in the accusative case?

herbata is the direct object (the tea being brought), so it takes the accusative case. Feminine singular nouns in the accusative end in -ę, and adjectives must agree in gender, number, and case: słodka → słodką.

Can you swap the order to herbatę słodką instead of słodką herbatę? Would that be correct?

Grammatically it’s possible (adjectives can follow nouns for emphasis or style), but the normal, neutral order is słodką herbatę. Saying herbatę słodką might sound poetic or marked.

Could we use podaje instead of przynosi, and what’s the nuance between these verbs?

Both przynosi (“brings”) and podaje (“serves/hand[s]”) can describe the waiter’s action. przynosi emphasizes transporting the tea from the kitchen to the table, while podaje highlights the act of handing or serving it to the customer.

How would you turn this statement into a yes/no question in Polish?

You can simply add Czy at the beginning and keep the word order:
Czy w restauracji kelner szybko przynosi słodką herbatę?
In spoken language, you can also leave out Czy and use rising intonation.