In English, verbs often change their form to indicate different tenses, such as present tense (e.g., "begin"), past tense (e.g., "began"), and future tense (e.g., "will begin"). The past tense of "begin" is used to talk about an action or event that started and finished in the past.
For example, you could say, "I began reading a new book yesterday." Here, "began" indicates that the action of reading started in the past.
It's important to note that irregular verbs, like "begin", do not follow the regular pattern of adding -ed to form the past tense. Instead, they have their own unique form. So, when talking about the past tense of "begin", we use "began" instead of adding -ed as we would in the regular case.
Remember to use "began" in the appropriate context when referring to past actions related to "begin".