“I like the sentence in the title of this thread. How do I check if they are correct?” “I have never seen any thieves in this town in the past 50 years.” “I always use \”never\” here if I haven’t lived much longer than 50 years.” “When I use \”have not\” it would mean that some thieves long ago, maybe 60 years ago.” “How will I tell the difference between a white list and a white list before I put it up online?” “Any questions are welcome.”