sentence 1: How do I know if I'm good?
 sentence 2: How do I know what I'm good at? sentence 1: What happens when I search for a number on Truecaller? Does the person receive any sort of notification about my search?
 sentence 2: How do I conduct a search on Truecaller? sentence 1: What are the best book for self learning Solid state physics?
 sentence 2: Which is the best book for solid state physics?
not same meaning
not same meaning
same meaning