"You slept early"
I guess ulilala = you slept (single) / mlilala = you (all) slept.
The course to English speakers can be confusing because both (singular and plural) are "you". That can be easier to a Portuguese speaker (você / vocês) or a Spanish speaker (usted / ustedes), for example.
It could be helpful if this course give to us some indication about if it's a plural or singular "you".