Have you ever thought about why we can't say "I'm gonna Pittsburgh"?
It's a reasonable question, once you think about the ways in which we use "gonna" in place of "going to." We can say things like "I'm gonna cry" or "I'm gonna get groceries" instead of "I'm going to cry" or "I'm going to get groceries." However, if you say "I'm gonna Pittsburgh" instead of "I'm going to Pittsburgh," you might be accused of trying to force a new verb into the language.
Listener Amber Sheerin brought the "Pittsburgh" conundrum to our attention after seeing a post about it on social media: "Why does 'gonna' work when we’re talking about actions, but not when we’re talking about destinations — even though, on the surface, it’s replacing the same words, 'going to'?"
The answer has to do with a process that linguists call grammaticalization. In this process, a content word — nouns, verbs, adjectives, and adverbs — becomes a grammatical element. Grammatical elements are things like prepositions, prefixes, suffixes, and auxiliary verbs.
For example, a noun or a verb will sometimes turn into a grammatical form. The verb "will," for example, started as a content word that meant "to want" or "to wish." We still use it that way when we say things like, "I will it to happen."
Over time, "will" got grammaticalized and became just a way to talk about the future. When we say things like "I will drive" or "I will call her," we're talking about what's going to happen, not wanting. Linguists call this loss of meaning "bleaching."
Something similar happened to "going to." The content verb "going to," expresses motion. However, "going to" has also gotten grammaticalized and bleached of that motion meaning and just means future. When you say "I'm going to call her," you're generally not talking about the physical act of going somewhere to make a call. You're talking about something you plan to do.
Sometimes in grammaticalization, we'll also see what linguists call "phonological reduction." In other words, some of the sounds of the word also fall out, and that's how "going to" becomes "gonna." So, that means there's a difference between "I'm going to Pittsburgh" and "I'm gonna go shopping."
To hear us unpack that, and to hear more about how "gonna" works, we're gonna recommend that you listen to the audio above.
