In and at for places

[mrmvp]

I am puzzled between using "in" and "at" for places .As far as I know is that "at" is more specific than "in".Is there a rule that can help me differentiate between them when talking about places , are "at" and "in" interchangeable?

1-I am in class or I am at class.
2-We are in cafeteria or we are at cafeteria.
3-We are in the class 8 or We are at class 8

I am aware of the differences between "at" and "in" is that "at" is used for time and "in" is used for months. There are other differences,however, I don't know which one is correct when talking about places and locations such as sentences one to three.

 

[emsr2d2]

I am puzzled struggling to choose between using "in" and "at" for places. Don't put a space before a full stop. Put a space after a full stop.

As far as I know, is that "at" is more specific than "in". Put a space after a full stop Is there a rule that can help me differentiate between them when talking about places? Are "at" and "in" interchangeable?

1. I am in/at class. or I am at class.
2. We are in/at cafeteria. or we are at cafeteria.
3. We are in/at the class 8. or We are at class 8

I am aware of that the differences difference between "at" and "in" is that "at" is used for time and "in" is used for months. There are other differences. However, I don't know which one is correct when talking about places and locations such as sentences one to three.

1. Both are possible.
2. Both are possible as long as you add the definite article before "cafeteria".
3. Only "in" is correct but you need to remove the definite article before "class".

The simple answer is no, there is no rule you can just learn. Preposition usage is one of the most difficult areas of English to master. It's a case of memorising examples each time you find one. Every time you spot a preposition when you're reading trustworthy English, make a note of the usage and the context.