So, if you've been mulling over the "may/might" issue (isn't that the sort of thing people love to do on Christmas Eve?), you might've come up with a scenario something like this:
A friend is way overdue to arrive at your Christmas Eve party up in the mountains. You and all your friends who did arrive OK are worried he might've had a mishap on icy roads.
"Ya think he might've crashed?"
"He may have simply decided to turn back."
"Ah, he might still show up: he may just be taking it real slow on those treacherous roads."
So, on that 2nd possibility, you're objecting, "I thought you said, Verbi, that 'may' is verboten in the past tense?" (Refer back to the previous entry, and the "definite past" reference.) Great question! I'm glad you asked.
Notice that in the 2nd example, the speaker is in the present, talking about a possible/hypothetical action in the past. So it's not the definite past (i.e. it hasn't been established yet. Maybe a day later, or a month later, they'll find out what really happened, and then, the whole episode will lie in the definite past.) The speaker is conjecturing about something that's still in limbo. In such a case, you may use "may." (But you could also use "might" there.)
