When you hear a /v/ sound at the conclusion of the term, it may have a silent e following it. Text like have and give, English pronunciation and spelling don’t normally match. This mismatch brings about mistakes like spelling “absolutely” as “definately”. dumbbell - The "b" in dumb is silent. https://spelling-rules-in-english52840.blog4youth.com/33418831/an-unbiased-view-of-spelling-rules-in-english