The speaker is living in a place where English is not their first language, and the poem keeps circling one worry: which language can actually carry what they feel? It starts with a grammar question, the "pre-position" needed, which also hints at being put in a position before one has even spoken. The speaker notices small things, like lowercase letters and the cautious way people ask "where are you from originally?", and shows how awkward and loaded that question can be.
Other immigrants appear too, missing the smells of kitchens and the greener gardens of memory. But the poem refuses to romanticize them. Being together in one place doesn't make people equal or friendly; they "rub against each other like shaken atoms."
The mood is reflective, uneasy, and a little wistful. Switching into Spanish near the end shows the speaker's divided state. The poem closes by repeating its opening question, leaving it unanswered.