So...this is really a pointless question, but I really want to hear people's thoughts: A sentence like, "I'm going to lunch with my mother." I always took the "to" in this instance as an independent preposition, and "lunch" is a noun, such as "I'm going to the store." But it dawned on me that perhaps "to" is being linked with "lunch" in this instance, to form an infinitive verb "to lunch," such as "I am going to buy a cat." (Yes, "to lunch" is a verb.) So it really doesn't matter, I know, but I want to know how it is generally thought of.