他在小声嘀咕什么？
What is he muttering about?
嘀咕
to mutter; to feel apprehensive
verb HSK 3.0 · Band 7
Watch it being written
Every character draws itself, stroke by stroke. Then grab the brush: trace it yourself and hear the word when you finish.
嘀
咕
Nice writing!
See it in sentences
别在心里嘀咕了。
Stop muttering to yourself.