"At THE front of..." Implies that the position is part of, and at the very front of, something. EX: She stood at the front of the line. (She is part of the line) EX: The hood (bonnet) is at the front of the car. (It is part of the car) EX: I had a seat at the front of the class. (I am part of the class) "In front of..." Implies a different position, separate, not part of. EX: I stood in front of the building. (I am separate from the building) EX: The teacher stood in front of the class. (The teacher is separate and facing the class of students) AT is the right choice for: "I stood at the bus stop"

It's always "at the front of". You need "the". in front of = facing; before; opposite (sometimes) at the front of = the foremost position I stood in front of the bus stop. (or just "I stood at the bus stop") I stood in front of the building. I had a seat at the front of the classroom. = student I had a seat in front of the class. = teacher, or student making a presentation I had a seat in front of the classroom. = um... your seat was just outside the classroom door. Were you checking tickets or something?

You can say AT the bus stop or IN FRONT of the bus stop. I prefer AT the bus stop, as does Google, as it is 10x more popular. You could say 'at the front of the bus stop' but this isn't really common. At the front of usually implies something that is big enough to need you to make it clear where you are standing, like 'at the back of' - 'at the side of' It's most usually 'IN FRONT OF the building' but 'AT THE FRONT OF' also works. 'I waited in front of the building for an hour.' or 'I waited at the front of the building for an hour'. I prefer 'in front of' because it is slightly easier to say and slightly shorter. That's all. And if your chair is at THE front of the classroom, then you are in front of the class. It's never usually 'in front of the classroom' because that implies it was outside the classroom. It's not very clear, I know, because the differences are very slight and there are no real reasons why.