A sonnet is a 14-line poem that rhymes in a pattern:
A - B - A - B - C - D - C - D - E - F - E - F - G - G
If the poem you're talking about meets these criteria, it is then classified as a sonnet.
1. Wood is to fire as food is to <u>substance.</u> - Wood creates fire the same way food is substance for people (plus here you have to use a noun, and substance is the only noun here)
2. Grinning is to cheerful as teetering is to <u>precarious</u> - precarious is something that is not balanced, and can fall at any moment
3. Conniving is to scheming as terrible is to <u>abysmal</u> - abysmal is something that is extremely bad or terrible
4. Mournful is to sad as gluttonous is to <u>voracious</u> - voracious means insatiable, always craving more and more
