English tenses express the timing of actions, events, or states. They help indicate when something happens (past, present, or future) and how it happens (progressive, completed, or habitual). 

There are 12 main tenses in English, categorized into three primary time frames (past, present, future) and four aspects (simple, continuous, perfect, and perfect continuous). They are all taught at different levels of English, so take your time before studying the more difficult ones. Here's a breakdown of all the tenses - present, past, and future.