diff --git a/ps-grammar/gprs/gprs.jsgf b/ps-grammar/gprs/gprs.jsgf
index f7f86449b42a11825ddab8e02bcbe1d936966c65..bbe8cdca1bcb573b88b28686f5ee42e74a86722f 100644
--- a/ps-grammar/gprs/gprs.jsgf
+++ b/ps-grammar/gprs/gprs.jsgf
@@ -28,7 +28,7 @@ public <task> = [<robot_name>] [(would | could) you] [please] <command> [please]
 <personal_pronoun> = (him | her | me);
 <person_name> = (james|john|alfred|daniel|charles|luis|paul|richard|robert|steve|anna|beth|carmen|jennifer|jessica|kimberly|kristina|laura|mary|sarah);
 
-<grab_object> = (<cleaning_class> | <drink_class> | <snack_class> | <food_class> | (cleaning stuff)  | drink | snacks | snack | object | food | something | stuff | item | beverage);
+<grab_object> = (<cleaning_class> | <drink_class> | <snack_class> | <food_class> | (cleaning stuff)  | drink | snack | object | food | something | stuff | item | beverage);
 <cleaning_class> = (brush | detergent | shampoo | sponge | toothpaste);
 <drink_class> = ((orange juice) | beer | cola | (chocolate milk) | (energy drink) | (grape juice) | milk | water);
 <snack_class> = ((chocolate cookies) | chips | biscuits | bread | pringles | (strawberry cookies));