Your Dexterity score increases by 2, and one ability score of your choice increases by 1.

You have darkvision out to 60ft.

You have proficiency in the Perception Skill

You have advantage on saving throws against being charmed or frightened. Magic cannot put you to sleep.

You can move through the space of a another creature that is of a size larger than yours.

Elflings don't need to sleep. They instead enter a restful state of mind. During which they dream somewhat normally, though overlaid upon their vision. They are still vaguely aware of their surroundings during this. They must do this for eight hours a day. After resting this way for eight hours they gain the same benefit a human does from eight hours of sleep.

You can speak, read, write, Common and Elven or Halfling.

Depending on your parentage, you may pick one subrace feature from any Elf or Halfling subrace from officially supported content.*

* Sometimes DM's will allow you to pick subraces of Elf or Halfling subraces that are not officially supported but are allowed in the campaign.
Please consult your DM before you do this.