In Hebrew, verbs, which take the form of derived stems, are conjugated to reflect their tense and mood, as well as to agree with their subjects in gender, number, and person. Each verb has an inherent voice, though a verb in one voice typically has counterparts in other voices. This article deals mostly with Modern Hebrew, but to some extent, the information shown here applies to Biblical Hebrew as well.

Verbs in Hebrew, like nouns, adjectives, and adverbs, are formed and declined by altering a (usually) three-letter stem, known as a shoresh (שורש transl. root). Vowels are added between or before these three consonants in a pattern to form a related meaning between different roots. For instance, shamar (שמר) "(he) kept / guarded" and katav (כתב) "(he) wrote" both add the vowel "a" in between the first and second consonants and second and third consonants to indicate the past tense "he" form. A similar formation can be found in English strong verbs with write-wrote-written and drive-drove-driven sharing root consonants despite differing vowels and meanings.

Hebrew verbs are further divided into strong roots (regular verbs, with occasional and predictable consonant irregularities), weak roots (predictable verbs irregular by vowel), and wholly irregular verbs.

A root that changes the vowel used in a given pattern is considered a weak stem. These are further divided into guttural (containing alef, hey, het, ayin anywhere, or resh as the second root), hollow (containing vav or yud anywhere, or hey as the final root), and repeating roots (beginning with nun or ending with two of the same consonant); based on exact irregularities. Weak verbs are detailed further below:

Guttural roots contain a guttural consonant (such as alef (א), hey (ה), het (ח), or ayin (ע) in any position; or resh (ר) as the second letter). Hey (ה) as the third letter is usually a hollow root marker due to being a vowel spelling rather than one of any consonant, and is only considered a guttural root in the third position if historically pronounced. Alef (א) root-initially and root-finally takes on a somewhat divergent conjugation similar to that of hollow roots, but is usually identical to other gutturals. Of the three classes of weak roots, guttural roots are the most common.

Roots containing a vav (ו) or yud (י) anywhere mark a historical vowel. Hey (ה) word-finally usually marks a final vowel for the same reason, and shares similar irregularities.

Roots containing two of the same letter or a nun (נ) in first position are considered repeating roots. Nun (נ) before a consonant doubles it or prevents beyt (בּ), kaf (כּ), and pey (פּ) from becoming veyt, khaf, and fey in word-medial position. Doubling consonants also changes the quality of the preceding vowel. However, doubling a consonant that doesn't change it outright (gemination) is obsolete in Modern Hebrew, and the irregularities usually affect the vowels.

When the initial letter of a shoresh is one of the sibilants zayin (ז), samekh (ס), tsade (צ) or shin (ש), then in Hitpa'el there is a phenomenon called metathesis, in which the sibilant trades places with a preceding tav (ת); in addition, the tav (ת) preceding a zayin (ז) changes to a daleth (ד) and the tav (ת) preceding a tsade (צ) changes to a teth (ט). E.g., מִזְדַּקֵּן, הִסְתַּכַּלְנוּ, אֶצְטָרֵף, לְהִשְׁתַּמֵּשׁ.