What You'll See Here

You have been waiting for her long enough.
We had been visiting Scotland for a few weeks when we discovered this village.
They will have been working here for two years next week.

Rule

To form the perfect continuous tenses, you will need to use the auxiliairy "to have", the past participle of the verb "to be" (been) and the gerund of the action verb.

Auxiliary to have	Past participle to be
have or had	been

To form the gerunds, follow these spelling rules:

Basic rule: Add -ing	Verb ending with consonnant - vowel - consonnant: Double the last consonnant + ing	Verb ending in -e: Replace -e by -ing
walk → walking eat → eating read → reading study → studying	travel → travelling knit → knitting jog → jogging rob → robbing	have → having come → coming hope → hoping decide → deciding
	*** if the last consonnant is a -w or a -x, do not double it! box → boxing chew → chewing fix → fixing