Let's say there is a married couple, Sandra and Jake. Sandra wanted to go to her ailing mother, whereas, Jake wanted to go on a holiday next week. If they didn't go to her mother:
if Sandra's mother were to become seriously ill, Sandra could not forgive here husband.
if Sandra's mother became seriously ill, Sandra could not forgive here husband.
This is a 2nd conditional modal verbs usage, and I know how to construct #2 sentence. But why is that were to become was used instead of the other?
If an ESL would like to use both of them, are they grammatical to use?
P.S.: There is a correct answer below, but, I have just edited this to clarify what I am really trying to ask.