Some translations set each line of poetry farther to the right than the rest of the text to make it easier to read. The ULB does this with the poetry in 11:9-10, 17, which are words from the OT.
The way in which Jesus entered Jerusalem, riding on an animal, was similar to the way a king would have entered a city after a great victory. And for the kings of Israel, it was traditional to ride on a donkey instead of on a horse. Matthew, Mark, Luke, and John all wrote about this event, but they did not all give the same details. Matthew wrote about there being both a donkey and a colt, but it is not clear which one Jesus rode on. It is best to translate each of these passages as it appears in the ULB without trying to make them all say exactly the same thing. (See:[Matthew 21:1-7](../../mat/21/01.md) and [John 12:14-15](../../jhn/12/14.md))