Correct spelling

control

Correct spelling, explanation: control is the correct spelling, because there is no need to double l at the end of the word. L is often doubled in case of adding some suffix, but here it is at the end of the word, so control is the correct form, not controll.

Definition of control:
noun, the act of controlling
Sorry, I don’t have any control over this issue.
verb, have charge of, curb
You should control your children more. They can’t just run and scream in public places all the time.

Idioms and phrases with control:
control freak, a person who is obsessed with having everything under their control
Sarah can’t share her duties with anyone, she’s a huge control freak.
be out of control, be reckless, become impossible to control
The car was out of control and crashed on the tree.


Incorrect spelling

controll

Incorrect spelling, explanation: this is an incorrect spelling, because l shouldn’t be doubled; the correct form is control. There is usually no reason to double this consonant when it is at the end of the word; it is often doubled when we add a suffix to the word, for example controllable. Here however control is the correct form, not controll.