The Arduino language is based on C/C++. It links against AVR Libc and allows the use of any of its functions; see its user manual for details.
those who explain how to program have no idea how to explain.
but nothing like trying to pick up Spanish... From that I taught myself C.
FOR I = 5 TO 50 STEP 5
Considering arduino is designed for people who have no prior electronics or programming experience I am astounded by the incompetence of the instruction pages.
You may as well ask for a "decent manual" on raising children.