Choose a song or rhyme your child hears often. Sing it together at a normal pace. Just before the last word of a line, stop singing and look at your child expectantly.
Wait three full seconds. Silence is doing the work — resist filling it.
If they supply the word, celebrate and carry on. If not, say it warmly and keep going. Pause at a different line next time.
Pausing before a predictable word turns a passive listen into an active retrieval. Filling the gap is a child's earliest experience of holding a word in mind and producing it on cue — a direct precursor to conversational turn-taking.