The verb "cost" is a straightforward word in English, used to indicate the price or value of something. It is a regular verb, following the standard conjugation pattern in English. In the present simple tense, "cost" follows the typical form for regular verbs: "I cost," "you cost," "he/she/it costs," and so on. For example, "The new phone costs $500."

In the past simple tense, "cost" becomes "cost" as well. This form is used to describe the price of something in the past. For instance, "The concert tickets cost $50 each last year."

Although "costed" is sometimes used as a past tense or past participle of "cost," it is less common and generally considered non-standard in formal English. The preferred and more widely accepted form is "cost." 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 cost more than we expected."

Understanding the regular conjugation of "cost" is important for accurately describing the price or value of items or services. The verb "cost" is also used in various idiomatic expressions, adding to its versatility in the English language.