Learn German: Das Buch ist sehr alt, aber der Text ist noch lesbar. - The book is very old, but the text is still readable.

It is built from the verb stem of lesen (to read). By dropping the -en and adding the suffix -bar, it becomes an adjective meaning "can be read" or "readable". Just like the English suffix "-able", it shows that an action can passively be done to the subject.

Can I express the meaning of lesbar using a passive sentence instead?

Yes! Words ending in -bar are often shortcuts for a passive sentence with the modal verb können. Instead of saying ...aber der Text kann noch gelesen werden (but the text can still be read), using lesbar is a more elegant and common way to express the exact same passive possibility.

Why doesn't the verb ist move to the end of the sentence after aber?

Because aber is a coordinating conjunction. It belongs to the ADUSO group (aber, denn, und, sondern, oder). These words take up "position 0" in the clause, meaning they do not affect the word order at all. The subject (der Text) takes position 1, and the verb (ist) stays in position 2.

Could I use immer noch instead of just noch here?