Four in a row.
Four fingers, one small thumb.
Four is the only number whose name in English has the same number of letters as it’s value.
Earth, water, fire and wind
and four rocky planets in the solar system;
Jupiter, Saturn, Uranus and Neptun.
Four basic states of matter;
Solid, liquid, gas and plasma.
On most computer keyboards the “4“ is also used to type the “$“ sign
Many animals have four feet and many humans have four wisdom teeth.
Most furniture has four legs.
In music, time is constructed of 4 beats per measure.
Four is also the number of strings on a violin,
a viola, a cello, double bass and a ukulele.
My daughter is now four years old.