This little poem is from Gartner's Dicteria Proverbialia (1598).
Hensellus quicquid teneris non discit in annis,
Hans nunquam discet, semper ineptus erit.
The vocabulary is keyed to the DCC Latin Vocabulary list. There is only one word in this poem that is not on the DCC list:
ineptus -a -um - silly, inept, foolish
annus -ī m.: year
disco -ere didicī: learn
in: in, on (+ abl.); into onto (+ acc)
nōn: not
numquam: never
quisquis quidquid: whoever, whichever
semper: always, ever
sum, esse, fuī: be, exist
teneo -ēre -uī tentum: hold