Learn Polish: Ta herbata jest zbyt gorąca, żeby ją wypić.

In Polish, to say something is "too X to do Y", you use zbyt (or za) before the adjective, followed by the conjunction żeby, and then the infinitive verb. You can literally think of it as "This tea is too hot, in order to drink it."

Why is the pronoun ją necessary here? English just says "too hot to drink".

Polish is much stricter about objects with transitive verbs. Because the clauses are separated by żeby, you must restate the object being drunk using the pronoun ją (referring to the feminine herbata). Dropping it and saying żeby wypić sounds incomplete and unnatural in Polish.

Could I use za instead of zbyt in this sentence?

Yes, you could say Ta herbata jest za gorąca... Both zbyt and za express excess meaning "too", but za is much more common in everyday spoken Polish. Zbyt is slightly more formal or typical of written Polish.

Why use the perfective verb wypić here rather than the imperfective pić?

Wypić implies finishing the tea or successfully drinking it as a completed action. Using the imperfective pić would focus strictly on the ongoing process of sipping it. In contexts like this, Polish naturally focuses on the inability to successfully "get the drink down", making the perfective aspect a better fit.