"is a commonality" is correct and usable in written English.
You can use this phrase when referring to a shared feature or characteristic that multiple things have in common. For example, "Living in a diverse environment is a commonality many people share."
What I've somehow found is a commonality.
Although there is a commonality of themes and motifs in Mr. Albee's plays -- broken marriages, lost and abandoned children -- he is unpredictable in his artistic choices.
Now a new study in The American Naturalist reports that there is a commonality among insects displaying this behavior: they have large, complex brain structures.
In a 2001 profile of her growing success in Time magazine, Oprah said "[There] is a commonality in human experience … If it's happened to one person, it has happened to thousands of others.
In a sense Indiana Jones sets out to find some kind of antiquity – often a paranormal antiquity – but he would also get caught up in the legend and become the story, so there is a commonality".
During my experience in Iraq, I observed how deeply connected and proud the Arab world is; despite the misgivings between some governments, tribes, and clansmen, there is a commonality that transcends borders.
"There's a commonality of the recognition of the value and importance of religion".
The real imperial glue had to be a commonality of interests and values.
It was a commonality of spirit rather than technical excellence that brought them their fourth win.
Some might call it sacrilege, but Kondakov believes there's a commonality between the two eras.
"With the Ganges, there was a commonality, with the spiritual aspect of how people interact with the river.
