In the following sentences (examples from Rosetta Stone):
- Ils payent avec des pièces.
- Elle paye par chèque.
- Il paye par carte de crédit.
- Je paye en espèces.
The first uses
avec, the second and third use
par, and the fourth uses
en. All of them refer to the method of payment but for me it looks like it is fine to replace one with another and also I don't understand how I can use them apart correctly.
So why is the preposition different depending on each method of payment?
And how can I decide which preposition to use if I don't know it in advance?