Final answer:
The sentence 'Suddenly, a thought struck Isaac like lightning' is an example of figurative language.
Step-by-step explanation:
The sentence 'Suddenly, a thought struck Isaac like lightning' is an example of figurative language. Figurative language is the use of language in a way that suggests special meanings or effects. In this case, the use of the word 'like' creates a simile, which is a type of figurative language that compares two unlike things using the words 'like' or 'as'.