This is apparently one of those confusing topics in English! But relax, it’s not as difficult as balancing a ball on your head and walking a tightrope—not even close. There is a slight difference between these prepositional expressions, but they can still be used interchangeably.
Both ‘in the front of’ (in the back of) and ‘at the front of’ (at the back of) indicate that something is in the frontal (or rear) part of another thing, and part of it. Let’s look at the difference and where they can be used interchangeably.
In the front of (in the back of)
-Smaller forms of transportation: e.g. a car, a boat with less space to move.
- She was sitting in the front of the car beside the driver.
- The trainer was calm as he stretched his legs in the back of the small boat.
At the front of (at the back of)
-Lines: as in a queue.
- She was at the front of the queue when the manager walked in and ordered everyone out.
- I didn’t realise the detective was at the back of the queue.
However, both expressions can be used for spacious forms of transportation, but we only use ‘in the front of/in the back of’ for smaller forms. We could say:
- The fire broke out in the front of the aircraft.
- He sat at the back of the train and slept off after a while.
Also, both can be used with rooms and buildings or with books.
- There were piles of newspapers at the front of/in the front of the restaurant after the attack.
- The author’s profile is in the front/at the front of the book.
Vividly, this is where the main difference lies: ‘at the front of/at the back of’ is used for lines; ‘in the front of/at the back of’ is only used for smaller forms of transportation.