This is vital. Use REALITY. Take in a bunch of different items. Different colored magnets, playing cards.
Use different verbs - hold, carry, drop, pick up, turn over, flip, flick, the only limits are your imagination.
As a native speaker you know which ones lend themselves to "was __ing" and which ones are "___ed". Illustrate the difference by showing a quick finished action v
0If you are teaching ESL to native Spanish speakers, the key is to tell them that the continuous past in the "imperfecto" in Spanish. For example I was waiting=Yo esperaba (Yo estaba esperando--this is literally the past progressive in Spanish, but they will relate well to the other). While the simple past would be "pretérito" I jumped=Yo salté.02br 02br 00¡Buena suerte! (