Many Spanish people like to use the construction "or and or" so they say something like "Or we can take the train or the bus". This is confusing for native speakers even though they probably will still understand you. To correct this mistake you need to use "either". So the correct way to say the same sentence is: "Either we can take the train or the bus".
Hope that helps!
Soy el director de Daniel Smith + Partners. Tengo más de 10 años de experiencia enseñando inglés a españoles.