Tart means a type of pastry shell filled with jam.
Or, acid, sour, sharp in meaning, which I love
because there were other words in English
that bit the tips of our tongues, or rendered
our mouths numb. (2342)
The poet writes of the duality of meanings in English words–for example, tart could mean pastry shell filled with jam, or acidic and sour and this duality could bring about trouble or hurt. The poet writes that these words “bit the tips of our tongues” or “rendered/our mouths numb” making them unable to communicate themselves as well. Suarez goes on to write about adolescent romances and the troubles of the label “friends” as a way of romantic rejection. I think this beginning few lines were an interesting way to begin a poem about duality in the English language and although the poet was writing of young love, it seems that this trouble of meanings in English words could also speak for those who learned English as a second language.