Grammatical tenses are forms of verbs that indicate the time of an action or state of being. They help convey whether an event is happening in the present, occurred in the past, or will occur in the future. The three main tenses are present, past, and future, each of which can be further divided into simple, continuous, perfect, and perfect continuous forms. Understanding tenses is essential for clear communication. For example, the present simple tense describes habitual actions, while the past perfect tense indicates an action completed before another past event. Mastering these tenses allows for more precise expression in both writing and speaking.