on all fours

Translations
(что-то) на четвереньках
The toddler was crawling on all fours.
Малыш ползал на четвереньках.
Definitions
A position where a person or animal is down on their hands and knees, with both hands and both feet (or knees) touching the ground.
Words
on

preposition
на
all

article or possessive pronoun
всех
fours

noun
четвереньках