There are many examples of using the verb "hast" instead of the copula "ast" in the Persian language, especially in informal speech and writing, but it is often considered a wrong usage and speakers are prohibited from it. This is because the verb "hast" is a lexical verb meaning "to exist", while "ast" does not have a lexical meaning and is only used as a copula. The present article examines the use of the verbs "ast" and "hast" and their allomorphs in the colloquial Persian language in terms of semantics and morphological structure in twenty-thousand colloquial sentences from the PARSMAP language corpus, which is a collection of selected sentences from social networks, blogs, e-mails, text messages and Persian stories. Considering the fact that these two verbs have a common root, and also referring to the speaking and writing problems of using the allomorphs of the verb "ast" in the colloquial language, and taking into account the fact that Persian speakers do not tend to use the verb "ast" in the informal situations, this article suggests that the verb "hast" as a copula in certain contexts replaces conjunctions such as "-e", "-s" and "-st". Expanding the use of the verb "hast" in some situations improves the readability of the text and helps the text processing and teaching the Persian script. It makes some compositions easier to pronounce and also makes the appearance of the text more uniform.