Learn Finnish: Eikö nainen viisastu yhä enemmän? - Doesn't a woman grow wiser and wiser?

The verb viisastua already means 'to become wise'. To express continuous change with a verb of changing state, Finnish pairs it with yhä enemmän (more and more). The literal structure is 'become wise more and more'.

How does the verb viisastu relate to the word for wise (viisas)?

It is formed using the verb-forming suffix -tua or -tyä, which attaches to an adjective stem to mean 'to become [adjective]'. This turns viisas into viisastua. Here it appears as viisastu because it is the connegative form after eikö.

Why doesn't the main verb viisastu have a third-person personal ending?

Because the sentence starts with the negative question word eikö (ei + the question particle -kö). Just like in a standard negative sentence, this forces the main verb into its stem-like connegative form without a personal ending.

Could I express this continuous change using the adjective instead of the verb viisastua?

Yes! You can use the verb tulla (to become) followed by the translative comparative: Eikö nainen tule yhä viisaammaksi? Both are natural, but using a dedicated change-of-state verb like viisastua is often more concise.