To look into something means to investigate or examine it more carefully. When your teacher says she'll look into why the classroom projector isn't working, she means she'll check what's wrong and try to figure out how to fix it. When a detective looks into a mystery, she gathers clues and searches for answers.

The phrase means taking time to explore, research, or investigate something thoroughly. If your parents say they'll look into getting a family dog, they mean they'll consider it seriously by researching breeds, thinking about costs, and deciding if it's practical. If a scientist looks into why bees are disappearing, she might spend years studying the problem.

People often use this phrase when they're not ready to make a decision yet but want to show they're taking something seriously. A principal might tell students, “I'll look into your suggestion about longer recess,” meaning she'll consider it carefully before deciding. The phrase carries a sense of responsibility: when someone says they'll look into something, they're promising to give it proper attention.