Learn Portuguese (Portugal): A neta costuma organizar qualquer atividade. - The granddaughter usually organizes any activity.

In Portuguese, habits are often expressed with the verb costumar rather than an adverb. You conjugate costumar for the person doing the action (here, costuma for the 'she' form matching A neta) and follow it immediately with an infinitive verb, which is organizar (to organize) in this sentence.

Why doesn't qualquer change to match the feminine noun atividade?

The word qualquer (meaning 'any') does not change based on gender, meaning it looks exactly the same before both masculine and feminine nouns. It does have a special plural form (quaisquer), but since atividade is singular, we just use qualquer.

I noticed atividade is spelled without a 'c'. Is that correct?

Yes! In modern European Portuguese, silent consonants have been officially removed from the spelling. Since the 'c' in the older spelling 'actividade' wasn't pronounced, it was dropped entirely, leaving us with atividade.