Hi I think I would say... - Our boss uses the surveillance camera to see if we are doing our work If you wanted a preposition for your sentence, I think it would be... - Our boss looks at us on the surveillance camera to see if we are doing our work Minor point - surveillance has 'e' before 'i' Best wishes, Dave
New words, one handy idiom, and a 2-minute quiz — delivered to your inbox to keep your streak alive.