Which sound device Is expressed by the words?

A big black bear blew a big black bubble

Alliteration

The sound device expressed by the words "A big black bear blew a big black bubble" is alliteration. Alliteration is the repetition of the initial consonant sounds in neighboring words. In this case, the "b" sound is repeated in "big," "black," "bear," "blew," and "bubble."

The sound device expressed by the words "A big black bear blew a big black bubble" is called alliteration. Alliteration is a literary technique that involves the repetition of consonant sounds at the beginning of neighboring words. In this case, the repetition of the "b" sound in "big," "black," "bear," "blew," and "bubble" creates an alliterative effect.