Questions & Answers about Niektóre kobiety twierdzą, że to zły pomysł.
Why do we use niektóre here instead of niektórzy?
The word kobiety (women) is a non-masculine-personal noun. In the plural, Polish splits words into masculine-personal (groups including at least one man) and non-masculine-personal (everything else, including women, animals, and objects). Because we are talking about a group of women, we use the non-masculine-personal form niektóre. If the sentence was about men, it would be niektórzy mężczyźni.
What is the dictionary form of twierdzą?
The infinitive is twierdzić (to claim or to assert). It is a regular verb in the present tense, and twierdzą is the 3rd person plural (they) form.
Why is the verb "is" missing in the phrase to zły pomysł?
Normally, saying "X is a Y" requires the Instrumental case. Why is zły pomysł in the Nominative case here?