Discussion Groups / English Usage / January 2010

Hello everyone

I just finished 「The Hidden Life of Otto Frank」 by Carol Ann Lee.
http://www.amazon.com/Hidden-Life-Otto-Frank/dp/0060520833

It's based on Otto Frank's life- the father of Dutch Jewish girl, Anne
Frank.

In the book, when Anne's friend Hanneli recalls that she met Anne by
chance in the camp in 1945, she says: 「Anne told me that her father
had been killed－her mother, too, she thought. It was a pity she
thought her father had died when he had not. The way she idolized him,
perhaps she would have had the hope to live if she knew he was still
alive.」

Why did she say: 「perhaps she would have had the hope to live if she
knew he was still alive.」 instead of 「perhaps she would have had the
hope to live if she had known he was still alive.」

In Somerset Maugham's 「The Razor's Edge」, when Isabel's distressed and
reproaches herself regretfully about her relationship with her lover.
Maugham says to her:」 If he loved you enough he wouldn't have
hesitated to do what you want." "I've said that to myself too. But it
doesn't help. I suppose it's more in woman's nature to sacrifice
herself than in a man's."

Why did Maugham say: 「If he loved you enough he wouldn't have
hesitated to do what you want." instead of 「If he had loved you enough
he wouldn't have hesitated to do what you want.」

I thumbed through some English grammar books (e.g. Practical English
Usage), it reads as follows: 「Sometimes a simple past tense is used
with if where a past perfect would be normal. This is more common in
American English.」 Michael Swan also puts this usage into 「if: other
structures found in spoken English」 category.

It's really just the informal usage in spoken English? That's all?
Does it have some other meaning?
Besides, I wonder why the present can affect the past in this informal
usage.

Could someone explain it for me??

Thanks!!