Si currat placidos tibi vis ut vita per annos,
Audi, multa vide, multa loquare cave.
Source: Philosophia Patrum (ed. Wegeler), 1258. Meter: Elegiac.
The vocabulary is keyed to the DCC Latin Vocabulary list. There is one word in the poem not on that list:
If you want (si vis) for your life (ut tibi vita) to course through tranquil years (currat per placidos annos), listen and observe much (audi, multa vide), but take care not to say too much (cave multa loquare).
I know the monkeys are not exactly a perfect match, but I thought they were so cute that it worked well enough, especially with the middle monkey having his hand over his mouth, which is the main message of the Latin poem! :-)
placidus, -a, -um: quiet, calm, gentle
annus -ī m.: year
audio -īre -īvī/-iī -itum: hear, listen to
caveo -ēre cāvī cautum: be on guard, beware
curro -ere cucurrī cursum: run
loquor loquī locūtus sum: speak, talk
multus -a -um: much, many; multō, by far
per: through (+acc.)
placidus -a -um: quiet, calm, gentle, kindly
tū tuī tibi tē: you (sing.)
ut, uti: as (+ indic.); so that, with the result that (+ subj.)
video -ēre vīdī vīsum: see
vīta -ae f.: life
volo velle voluī: wish, be willing