the problem that i used to have with prepositions is that i used them by translating from my native language. Thanks god i don't have this problem any more and i have understood the true nature of english language to a great extent. I have solved quizzes on your website which gave me a result in percentages between 80 and 90. Is this enough for me so that i can put my attention to other different areas of english. by the way, how would you rank me in the use of prepositions.
The prepositions in your post are well nigh immaculate, Zaffar. It's time to move on to other things. How about studying the rules for capitalization?