Like any polite person would do, our speaker starts off by answering a question. Apparently the question that has been put to her is: "Just what in the wide world of sports are you talking about when you say 'I lost my tongue'?" Trickily, our speaker answers this question with a question of her own.
That question essentially is: "What would you do if you had two tongues in your head and then you lost one of them?" The lost tongue is the "mother tongue" (5) and the one our speaker has left is "the foreign tongue" (7). And then, she continues, let's say that you couldn't really know that foreign tongue, and that you couldn't use them both at the same time—even if you thought that way (both in your native and adopted language). If you had to live somewhere where you could only speak with the foreign tongue, then your mother tongue would "rot and die in your mouth" (13)—ew.
At least, this is what our speaker thought happened to her—until she had a dream. And then—boy howdy—the poem takes a sharp left turn. We move from the middle of this thought into a section of Gujrati writing (Gujarat is a state in northwest India). After each line, we get a helpful line in parenthesis of how to pronounce those Gujrati words.
Then, after this section concludes, we get the English translation of the Gujrati section. It picks up right where the last line in English left off, explaining that the mother tongue grows back while the speaker dreams. She describes the new tongue like a plant, choking off the foreign tongue and then starting to bud in the speaker's mouth.
This sounds pretty unnerving, but the speaker doesn't seem to mind. She tells us that, every time she thinks she's forgotten her mother tongue, it comes blooming out of her mouth. And with that, our speaker is done speaking.