On Alchemy
Latin Grammar: Possum
Unde in quibusdam aquis alchimicis, quae per effectum manifestantur alterius speciei, quia convertunt metalla, quod non est effectus aquae, et si moveantur, stant et non fluunt, non posset fieri baptismus, et similiter in iure olerum, quia non manet effectus mundandi. Sed in aqua calida potest, quia licet per violentiam sit in contraria dispositione, manet tamen naturalis virtus ad infrigidandum.
Possum: No, not the animal. This is the Latin verb for "to be able." It is formed irregularly, and it appears frequently in Latin texts everywhere. The principal parts of possum are possum, posse, potui. Note the absence of the fourth principal part.
Form the present tense of possum in all persons, singular and plural. If you have trouble remembering the forms, remember that possum starts just like the form sum of the verb esse.