I have read such sentence from native English speaker who used that phrase.
I am100% that the [color=red]They were is right. However, it still makes me confuse if the They was is also right or applicable to any circumstances, please correct me.
I really don’t know if the “they was” is correct or wrong. What I know is that, “They” is plural and should be followed with “were” for plural pronouns. It should not be “was” right?