Incorrect spelling, explanation: some users of English double the letter -p in the word apart, which results in an incorrect form appart. The mistake is the effect of the pronunciation, which sometimes gives the impression of a double -p letter. However, the form is wrong so do not use it.

Correct spelling, explanation: Latin a parte, which means at the side, is the root of a contemporary English word apart. The word is mainly an adverb but has quite a number of meanings as it is an important part of many English expressions and collocations.

Definition of apart:
1. adverb – means that something or somebody is separated or far away from one another, it can also mean that something is damaged or falling into small pieces.
We lived a hundred kilometers apart from each other so after some time we lost touch.
My car is falling apart, I don’t know if there is a mechanic who could handle it.

Collocations and expressions with apart:
1. tear apart – to give a critical opinion on somebody or something,
His mother tore him apart after he failed the exams.
2. joking apart – when you want to show that jokes are over and it’s time to start talking seriously,
Joking apart, will you at least consider my offer?
3. poles apart – totally different from one another,
My parents are poles apart when it comes to personality, my mother is cheerful while my dad is usually very serious.