Comer vs. comerse
In Spanish, both 'comer' and 'comerse' can be translated to 'to eat' in English, but they have slightly different uses and connotations.
Comer
'Comer' is the basic verb that means 'to eat'. It is used generally when referring to the act of eating.
Voy a comer una manzana.
(I am going to eat an apple.)
¿Quieres comer algo?
(Do you want to eat something?)
Comemos juntos todos los domingos.
(We eat together every Sunday.)
Comerse
'Comerse' is a pronominal form and implies eating up or consuming something entirely. It often adds emphasis or indicates that something specific is being eaten completely.
Se comió todo el pastel.
(He ate up the whole cake.)
Los niños se comieron las galletas.
(The children ate up the cookies.)
Me voy a comer este sándwich.
(I am going to eat up this sandwich.)
Summary
While 'comer' is used for the general act of eating, 'comerse' emphasizes the act of consuming something entirely. The choice between them depends on whether you want to specify that the entirety of something is eaten.