I learned that "[verb] + ing] is a gerund. But the word "thinking" is a noun. How do I distinguish the gerund and noun?

Rebecca

Good question! The noun "thinking" means "thought process," so if you can replace "thinking" with "thought process," it would be a noun. Gerunds can also be followed by an object, but nouns can't! Ex: I'm thinking about going on vacation. => present participle Ex: What is your thinking behind this decision? => noun = What is your thought process behind this decision? Ex: I like thinking about the future. => gerund