How do you tell wjen a guy is into you?

You can often tell a guy is into you by his body language, such as maintaining eye contact, leaning in when he talks to you, or mirroring your movements. He may also engage in playful teasing or compliment you frequently. Additionally, if he initiates conversations, makes an effort to spend time with you, and shows genuine interest in your life, it's a strong sign that he's interested.