A job billed as "character-building" may be one of unending stress.<br/><br/>In the sentence above, why "stress" does not ends with an "es"—as plural? <br/><br/>To put the sentence as a whole, this is what I would have said:<br/><br/>A job billed as "character-building" may be one of unending stresses.<br/><br/>Thanks in advance,<br/>Kallag