Some quotes from Wallace about the distinction of present/aorist imperatives (pages 716-18)

[the traditional view suggests that] the aorist in pro­hibitions meant do not start, while the present in prohibitions meant stop doing.


[McKay’s suggestion is that] the essential difference between the aorist and the imperfective is that the former urges an activity as whole action and the latter urges it as ongoing process.


[Wallace summarises] the basic force of the aorist in commands/prohibitions is that it views the action as a whole, while the basic force of the present in commands/prohibitions is that it views the action as ongoing process. This basic meaning may, of course, be shaped in a given context to fit, say, an ingressive idea for the aorist. Thus if the con­ditions are right, the aorist prohibition may well have the force of “Do not start.” This is an affected meaning or specific usage. But to call this the essential idea is not correct.


Quick Tip: Identical Forms

The Hithpael conjugation has four identical forms. In one sense, this is good news – a few less things to memorise. In another sense, it makes things a little confusing.

The form in question is: הִתְפַטֵּל.

This could be:

  1. 3ms perfect – this is simply the basic Hithpael form.
  2. 2ms imperative – the Hithpael imperative is formed by taking the imperfect conjugation, removing the prefixed yod/taw and adding a prefixed he. So the form is derived: תִּתְקַטֵּל > תְקַטֵּל > הִתְקַטֵּל.
  3. infinitive construct – as in all conjugations (apart form Hiphil) the infinitive construct is identical to the 2ms imperative.
  4. infinitive absolute – in (only) the Hithpael, it just so happens that the infinitive absolute is also identical to the 2ms imperative

Thus, there are four identical forms in the strong verb.