Conjugating pa-in and pa-an verbs...

@Kersheys "Pinatutulog" and "pinapatulog" just mean the same thing. That is true for other pa-in, pa-an, and pag-an verbs. Since the standard rule for the present/uncompleted conjugation is to repeat the first syllable (or part of it) of the root word, "pinatutulog" should be the corresponding standard form. However, based on usage, I think one form is just as popular as the other. pinapakain - pinakakain
pinapaisip - pinaiisip
pinapaalis - pinaaalispinapasabihan - pinasasabihan
pinapatawagan - pinatatawagan
pinapalakaran - pinalalakaranpinapagsabihan - pinagsasabihan
pinapag-isipan - pinag-iisipan
pinapaglagyan - pinaglalagyan
pinapagtaguan - pinagtataguan

@Juantutri Thank you, out of interest is the "pinapatulog" form a more modern variant?

@Kersheys I don't think so. I've been hearing both forms even from older people ever since. Possibly it's a regional variation. That some might find one form easier to pronounce than the other could have also been a factor.