* Formal: "The evidence presented was insufficient to secure a conviction."
* Everyday: "The instructions were insufficient; I still don't understand how to assemble this furniture."
* With a specific noun: "Due to insufficient funding, the project was delayed."
* Focusing on the result: "Insufficient sleep left her feeling irritable and unproductive."
* More complex sentence: "His attempts to explain the situation were insufficient to alleviate her concerns, leaving her feeling increasingly frustrated."
The word emphasizes a lack or shortage of something that is needed.