Tense is a grammatical concept that indicates the time when an action occurs. It helps us understand whether an event is happening in the past, present, or future. For example, in the sentence "She walks to school," the verb "walks" is in the present tense, showing that the action is currently happening. There are three main tenses: past, present, and future. Each of these can be further divided into simple, continuous, perfect, and perfect continuous forms. For instance, "He played soccer" is in the past simple tense, while "He will play soccer" is in the future simple tense.