We've been working this song with 1st level of Primary. Here you'll find two versions to sing. The first one is by Taylor Swift with subtitles. The second is the one we have worked in the class.
The way we have learnt it is repeating only the last word of each line after me. I made a silence at the end of each line, and then children sing the missing word.
At the end, some of them even sang the entire line!
Merry Christmas and a special wish of happiness for all my pupils!