Edit file qa-include/qa-lang-question.php. Find these 3 lines and modify them accordingly:
'a_your_waiting_approval' => 'Your answer will be checked and approved shortly.',
'c_your_waiting_approval' => 'Your comment will be checked and approved shortly.',
'q_your_waiting_approval' => 'Your question will be checked and approved shortly.',
Alternatively, if you don't want to perform a core hack you should use your translation folder:
qa-lang/sp/qa-lang-question.php. In this case sp stands for spanish (current language).
Alternatively, if you don't want to change the language files you can also create the file qa-lang/custom/qa-lang-question.php. It should only contain:
<?php
return array(
'a_your_waiting_approval' => 'Your answer will be checked and approved shortly.',
'c_your_waiting_approval' => 'Your comment will be checked and approved shortly.',
'q_your_waiting_approval' => 'Your question will be checked and approved shortly.',
);
It will override your current language files
