Hello again.
I have a listening exercise for you, giving examples of IF sentences.
http://englishgrammarsecrets.com/listening22/menu.php
This will not work with many tablets and phones.
My son had a fantastic time in Nepal a few years ago. He didn’t quite make it to Everest base camp because of altitude sickness but he climbed a peak next to Everest. He was treated with great kindness wherever he went. My heart goes out to that country at this time.
Use of let