לא

From Proto-Semitic *lā.

לָא • (lā)

1. no, not

• אין‎ ('en, “yes”)

From Proto-Semitic *lā. Cognate with Arabic لا‎.

• (Modern Israeli Hebrew) IPA^(key): /lo/
• (Biblical Hebrew) IPA^(key): /loːʔ/
• Homophone: לו‎
• Rhymes: -o

לֹא • (lo)

1. Not; used in negating verbs, adjectives, and adverbs.

• לא is not used to negate verbs in the imperative; rather, in ancient texts negative imperatives consist of לא and a verb in the second-person jussive, and in modern use they consist of אל‎ (al) and a verb in the second-person future. However, even in modern use, לא may be used together with a to-infinitive to create what might be called a "general negative imperative", where no specific person is being addressed. (The general negative imperative might be better viewed as a kind of declarative, however, as it can be used in a subordinate clause.)
• Hebrew does not require a "dummy auxiliary verb" to negate a verb; for example, English "I didn't go" corresponds to Hebrew לא הלכתי (lo halákhti, “not went-1ST-PERSON-SINGULAR”).
• לא cannot be used to negate יש‎ (yesh, “there is, there are”); rather, its negative counterpart אין‎ (ein, “there isn't, there aren't”) must be used.
• In formal Hebrew, clauses of the form <subject> לא <verb in present-tense, adjective or noun phrase> (meaning <subject> don't/doesn't <verb> or <subject> isn't/aren't/am not <adjective or noun phrase>) are typically recast using אין‎ (ein) in its inflections.
• לא can stand in for an entire negative clause, rather like English not or an English auxiliary verb plus not, but a bit more flexibly.

לֹא • (lo)

1. No; used in responding to questions.

• אֵין‎ (en, ein)
• אַיִן‎ (ayin)

• אל‎