Another "SE" question

Hola, Here is another question about "SE" In Pimsluer's course they have the phase: El cajero automatico se ha comido mi tarjeta. When does one know when to use "se" in a phase like this???

Hola. Benvenido al foro. The quick answer for "how do you know when to use se" is that you learn by hearing and reading. In the case of comerse, I think there are some rough guidelines. You'd use comerse rather than comer if you are emphasizing the extremity of the action--you didn't just eat it, you ate it up or you gobbled it up. Another time you'd use comerse is when you're suggesting something unexpected, as in the case of the Pimsleur example. I highly recommend the discussions at the WordReference.com forums. I did a search on comerse and got lots of hits, including several that asked specifically about comer vs. comerse. See, for example, this one: __http://forum.wordreference.com/showthread.php?t=887756__. And here's the URL to the list I got: __http://www.wordreference.com/es/en/translation.asp?spen=comerse__. I hope this helps.