General expressions:
* Ko dára: This is the most basic and direct translation of "not good." It simply means "it is not good."
* Kò dára gan-an: This emphasizes the lack of goodness. It literally means "it is not good at all."
* Kò dára tó: This means "it is not good enough." It implies that something is lacking or not satisfactory.
More nuanced expressions:
* Kò se mọ́nà: This means "it is not good enough." It implies that something is inadequate or not up to par.
* Kò bá mi mu: This means "it doesn't please me" or "I don't like it." It expresses personal dissatisfaction.
* Kò dára, ó ní kíni: This means "it is not good, it has something wrong with it." It indicates that there's a specific problem or flaw.
The best option for you will depend on the specific situation and what you want to communicate.