The verb "do" is an irregular verb in English, commonly used to indicate action or performance. Its conjugation deviates from regular verbs. In the present simple tense, "do" follows its base form for most subjects: "I do," "you do," "he/she/it does," and so forth. For example, "She does her homework every evening."

In the past simple tense, "do" changes to "did." This irregular form is used to recount actions that took place and concluded in the past. For instance, "He did the dishes after dinner."

The past participle of "do" is also "done." When forming perfect tenses, such as present perfect or past perfect, the past participle is combined with auxiliary verbs. An example sentence is "They have done a great job on this project."

Understanding the irregular conjugation of "do" is essential for accurately describing actions related to performance or completion of tasks. Whether used in questions, negatives, or emphatic statements, the verb "do" is fundamental in the English language.