Montar en/a - I would like to ask whether there is any difference between montar en and montar a or whether they can be used interchangeably?

Hola Emanuel

Montar a is only used for "riding a horse", "Yo monto a caballo".

Montar en is used for any other case, "Yo monto en bicicleta", "Ella se montó en el coche", "Mi hijo entá montado en el burro."

Saludos

Inma