Swedish uses the prepositions on and at far more than any others, meaning that they tend to overuse them in English. Prepositions of place and time are the hardest to remember, and the more you train them, the worse the problem tends to become. It is very easy to let a grammar checker do the work if you are writing, but speaking is full of traps. Reading is the only thing that really helps internalise prepositions, with watching films or television coming second.
This chart explains it better than I have ever been able to.
