I am not an American. I think it is in America where they invented the idea of singular they. You don't know the gender of someone, you refer to him/her as they. I am thinking if I should use the verb alone or verb + s/es after a singular they.
An example to highlight my idea.
Someone named Ekadh close voted my question. They think/thinks my question is off-topic.
Should I use think/thinks here? I know Ekadh is a person, one person, whose gender I don't know.