The Eldar grew in bodily form slower than Men, but in mind more swiftly. They learned to speak before they were one year old; and in the same time they learned to walk and to dance, for their wills came soon to the mastery of their bodies. Nonetheless there was less difference between the two Kindreds, Elves and Men, in early youth; and a man who watched elf-children at play might well have believed that they were the children of Men...

...at the end of the third year mortal children began to outstrip the Elves, hastening on to a full stature, while the Elves lingered in the first spring of childhood....

Not until the fiftieth year did the Eldar attain the stature and shape in which their lives would afterwards endure, and for some a hundred years would pass before they were full grown.

The Eldar wedded for the most part in their youth and soon after their fiftieth year.