Illocutionary Force Type. Strength or emphasis put on a phrase. Speech act information - meaning you want to convey above and beyond just the words spoken. As an example, the English phrase `I understand' can mean `Thank you for informing me (I'm happy)' or `Now I know what you intend I'm not happy' or even `I heard what you said but haven't a clue what you mean' depending on how and when it's said. That's IFT at work. The simplest case is the difference between a question and a statement using the same words.