I can't clearly understand why
1) My wife will be angry unless I get home by 7 o’clock. - is not correct while
2) My wife will be angry if I am not home by 7 o’clock. - is correct.
Any guiding line?
Both are correct - if...not is what unless means. But the unless version suggests that her anger is expected, and only my arriving at or before 7 o'clock will prevent it, while the if...not version suggests that my arriving after 7 o'clock will trigger her anger.