The past tense in English grammar is used to describe actions or events that happened in the past. In English, there are two main types of past tenses: the simple past and the past continuous. The simple past is used to talk about completed actions in the past, while the past continuous is used to describe ongoing actions or events that were happening at a specific time in the past. Additionally, we have past perfect and past perfect continuous tenses to describe actions that happened before another action or time in the past. Understanding and practicing the use of past tense forms is essential for effective communication in English.