I have a very strong grasp on C with over 6 years of C programming experience and am a contributor to open-source GCC compiler. I have a distinct advantage over others in that, I know the internals of C compiler and hence know the language intimately. Being a compiler developer, I can explain crucial but less well-known concepts of C like undefined behavior, sequence points, complicated declarations, dynamic allocation, processor architecture's influences like ABI, calling conventions, machine-endianness reasonably well along with grab-bag of C idioms and tricks which encourage good programming style and writing clear, robust and fairly optimized code. I have been invited for guest lectures on C programming in local colleges in my native city (Pune, India), and the reviews were generally positive. If you need any other details feel free to contact me. Thank you.