Hello! Filler words in English are words that you use as "fillers" in conversation. They don't really mean anything, but they keep the conversation going and they make it sound more natural. Native speakers use filler words very often. Some example of filler words are "erm", "like", "uh", "well", "basically", "I mean", "actually"... Here is a sentence with some filler words: "Well, that's not really what I wanted to say, I mean, she's a good student but she's not, like, one of the best or anything. Erm... it's hard to explain." I hope to have helped you!