Something inspirational gives you encouragement, or a new idea of what you might do. Speeches, teachers, books, and films get called inspirational when they lift people and point them somewhere. There is a rarer noun use too: people sometimes talk about inspirational as a kind of writing or music meant to lift you. Though actually, the word has picked up a slightly shiny, poster-on-the-wall feel. An ‘inspirational speaker’ is almost a job title now; an ‘inspirational quote’ on social media may or may not move anyone. Inspiring is the sister word that still sounds more like a real feeling in the room. Careful speakers use inspirational for the thing offered (a talk, a book) and inspiring for how it lands on you — but people mix them, and nobody at the dinner table is marking that line.