The Tern; The Turnip

To tell the Turnip from the Tern,
A thing which everyone should learn,
Observe the Tern up in the air,
See how he turns, and now compare
Him with this in‑ert veg‑et‑able,
Who thus to turn is quite unable,
For he is rooted to the spot,
While as we see, the Tern is not:
He is not always doomed to be
Thus bound to earth e‑tern‑ally
For “cooked to a tern” may be inferred,
To change the Turnip to a bird.

Observe the Turnip in the Pot.
The Tern is glad that he is not!