If you are a boy, short in Spanish is 'bajo' (ba as in ball and Jo as in hole). If you are a girl, short in Spanish is 'baja' (ba as in ball and ja as in hall).
Either corto/corta or bajo/baja (low).
Short man = hombre corto
If you are speaking of objects, use "corto/a". When speaking of a person, use "bajo/a".
los pantalones cortos
Shorts or pantalones cortos
pantalones=pants pantalones cortos=shorts or just say shorts but shorts as in underwear is calzones(same word for mens or womens underwear)
pelo corto y negro
"Short" in Spanish is usually "corto", but when applied to a person, you would say "bajo". For feminine objects, substitute an "a" for the final "o".
Shorts kaki.
me gusta llevar pantalones cortos en el verano
Literally, this is "pantalones cortos de baloncesto". There may be an idiomatic expression for this, but I am not familiar with one.
Shorts (piece of clothing) are called the same in French: un short, des shorts.
SHortay
As in the clothing? You would say, "I wore shorts to the game. I wore two different pairs of shorts to the game." So you could use pairs, if you want. But the plural of shorts would be shorts.
I would say that Nike Running Shorts are a type of exercise attire. From personal experience Nike running shorts are comfortable cause they seem to move with you and not stick to you like some other types of shorts do.
I wouldn't say that they run bigger, but they do fit different then jean shorts. They are less tight and less restricted and not as short as jean shorts.