This is the 950th most frequent French word.
quelqu
The word "quelqu" is not complete; it is likely part of "quelque," which means "some" or "a few" in English.
Here, 'quelqu'un' is used as an indefinite pronoun to refer to an undefined person.
Quelqu'un est à la porte.
Someone is at the door.
In this example, 'quelque chose' functions as an indefinite pronoun meaning 'something'.
Il cherche quelque chose en cuisine.
He is looking for something in the kitchen.
'Quelques' here acts as an indefinite adjective modifying 'livres,' indicating an unspecified small number.