Yes, some people do say "I'm going cry" instead of "I'm going to cry," but it is considered informal or colloquial speech. This type of language usage is often referred to as "ellipsis" or "omission" of words, where certain words are left out for brevity or casual conversation.
When people use ellipsis or omission, they are skipping certain words that are understood in the context of the conversation. It can happen in spoken language and informal writing, like text messages or social media posts.
The phrase "I'm going cry" is an example of ellipsis, where the word "to" is omitted from the phrase "going to cry." The complete and grammatically correct version would be "I'm going to cry." In casual settings, people may omit words like "to" to express their emotions more quickly and informally.
It's essential to recognize the appropriate context for using informal language. While it's acceptable in casual conversations, texts with friends, or social media posts, it's generally not appropriate in formal or professional writing. In formal contexts, it's better to use the full and grammatically correct version of the sentence.