i- is used when someone does not know what to say, usually because of a surprise or shock. Sometimes you feel surprised after what has been said.
Let’s understand it with an example.
Person 1: I know you want to marry me.
Person 2: i- know that I don’t really know anything.
Many people use slangs and acronyms in their texting. Texting slangs/abbreviations/acronyms convey the message in a few letters or numbers. These are usually used on social media platform likes Twitter, Facebook, Instagram, . Snapchat WhatsApp etc.