Correct spelling


Correct spelling, explanation: this word is a combination of the verb open and the ending -ing, which is necessary to form the present participle or gerund. -Ing is one of the most common suffixes. When creating a derivative, always remember to look at its root. If you add -ing to open, you get a word spelled opening. There’s no reason to add an extra consonant to it.

Definition of opening:
verb, making available for or active in a regular function
My mother was opening her new store at that time.
I was just opening my book when Mark walked in.

Incorrect spelling


Incorrect spelling, explanation: since gerund/present participle forms are derivatives of verbs, the word opening must accord with its root, which is the word open. We have to remember not to add any extra consonants to it. Now it should be clear why the only right version is opening, not oppening.

Incorrect spelling


Incorrect spelling