When it comes to categorizing and labeling Hebrew verbs, we can do so in several ways. First, we can look at what general patterns (“stems” or בִּנְיָנִים) the verb appears. This is similar to Latin’s verb conjugations, by which nouns are categorized by the forms they take in the infinitive (whether -āre, -ēre, -ere, or -īre). In Hebrew, roots may appear generally in seven stems, though there are a few outliers here and there in peculiar stems as well, and we can label verbs as “qal” or “piel” or “hiphil” (or whatever stem they appear in by their nature).
Another common way to group Hebrew verbs is by the gutturals or vowel letters that they contain and the position in which they are found in the root.
The guttural letters are ʾalef (א), heh (ה), ḥet (ח), and ʿayin (ע). Resh (ר) is sometimes included in the list because it behaves similarly to them. The vowel letters (know in Latin as matres lectionis) are heh (ה), vav (ו), and yod (י). Notice that heh is both a guttural and a mater lectionis (sg. of matres lectionis). Since nun (נ) tends to assimilate into other letters, many roots with nun are also considered weak, depending on its position in the word. When these letters appear in a root, they mess up the normal pattern, and those mess-ups are predictable and regular.