warn

"He is a student of life."

"My friend told me there was something in the box, but I didn't know what it was yet. "

""The farmer put up a sign warning trespassers to stay off his land." "

"The teacher had to admonish the students to be quiet during the test. "

"My daughter's teacher is very kind and helpful. "

"Do you need a gift for that special someone?"

"Late arrival to class is an unacceptable reason for missing the test. "

"My sister is very helpful, especially when it comes to organizing things. "

"The dark clouds impending over the city threatened a sudden downpour. "

"The upcoming school holiday is a welcome break for the students. "

"The teacher's caution about the upcoming exam helped the students prepare better. "

"The teacher praised Sarah's good behaviour in class. "