The phrase "are certainly common" is correct and usable in written English.
It can be used to emphasize that something is frequently encountered or widely observed.
Example: "In many cultures, certain superstitions are certainly common, reflecting shared beliefs and practices."
Alternatives: "are definitely prevalent" or "are quite frequent."
Delusions of grandeur are certainly common: "American Idol" presents a limitless supply of talentless narcissists, each convinced he is the next Frank Sinatra.
There are certainly common trajectories to these cities' woes, and seemingly intractable problems, from post-colonial re-constitution to bloody conflict, corruption to water shortages, lack of health care to disease.
Marketing isn't really about getting more audience share or even a few more leads, though those are certainly common goals.
The list may seem random, but as Pearson points out,"There are certainly common threads and specific skills underneath them--AI, robotics, computer vision and machine learning.
Conflicts are certainly common between tour operators and hunting outfitters when they are competing for land and wildlife (e.g., around the Okavango Delta in Botswana and the Luangwa Valley in Zambia), but such problems seldom arise when the same manager is responsible for both operations, as in the Pilanesberg example.
Reminders of sex are certainly common in our society, from the advertisements on the subway to the attractive people on the subway who make us think about sex.
"It's certainly common for the board to want to interview a prospective purchaser in person," he said.
Acts easily transfer back and forth, and a spiritual overlay -- an implication that the pageant hints at a quest of the spirit -- is certainly common to both.
This kind of collaboration is second nature to Patterson from his advertising days, and it's certainly common in other creative industries, including television.
It has no chance of poisoning the mainstream of discourse again.Racism among Europe's longer-standing indigenous populations towards newcomers often with darker skins is certainly common and may have become more acute as the numbers swell.
We see here the re-emergence of an element of alterity proper to the statute of the group, but which here is still formal: the third party is certainly the same, the praxis is certainly common everywhere; but a shifting dislocation makes it totalising when I am the totalised means of the group, and conversely.
