laravel/application/lang/en/validation.php

<?php 

return array(

	/*
	|--------------------------------------------------------------------------
	| Validation Error Messages
	|--------------------------------------------------------------------------
	*/

	"accepted"   => "The :attribute must be accepted.",
	"active_url" => "The :attribute does not exist.",
	"alpha"      => "The :attribute may only contain letters.",
	"alpha_dash" => "The :attribute may only contain letters, numbers, dashes, and underscores.",
	"alpha_num"  => "The :attribute may only contain letters and numbers.",
	"between"    => "The :attribute must be between :min - :max.",
	"confirmed"  => "The :attribute confirmation does not match.",
	"email"      => "The :attribute format is invalid.",
	"image"      => "The :attribute must be an image.",
	"in"         => "The selected :attribute is invalid.",
	"integer"    => "The :attribute must be an integer.",
	"max"        => "The :attribute must be less than :max.",
	"mimes"      => "The :attribute must be a file of type: :values.",
	"min"        => "The :attribute must be at least :min.",
	"not_in"     => "The selected :attribute is invalid.",
	"numeric"    => "The :attribute must be a number.",
	"required"   => "The :attribute field is required.",
	"size"       => "The :attribute must be :size.",
	"unique"     => "The :attribute has already been taken.",
	"url"        => "The :attribute format is invalid.",	

	/*
	|--------------------------------------------------------------------------
	| The following words are appended to the "size" messages when applicable,
	| such as when validating string lengths or the size of file uploads.
	|--------------------------------------------------------------------------
	*/

	"characters" => "characters",
	"kilobytes"  => "kilobytes",

);