In short

Modern Hebrew’s past tense works on a different principle from the present. Where the binoni (lesson 6) marked only gender and number, the past marks person — I, you, he, she, we, they — by hanging a suffix on the root. So on the very same three letters כ־ת־ב (k-t-v, “write”) you get כתבתי (katavti, “I wrote”), כתבת (katavta, “you wrote”), כתב (katav, “he wrote”), כתבה (katva, “she wrote”). This lesson builds the full set for the base binyan pa’al on strong (שלמים, shlemim) roots — the fully regular ones with three solid consonants.

Because the ending itself names the subject, the pronoun becomes optional: כתבתי on its own already means “I wrote”. The form to memorize is the third-person masculine singular, the bare CaCaC stem — כתב (katav), למד (lamad), שמר (shamar) — and every other person is that stem plus a person-suffix.

The rule

• The past marks person, unlike the present. In the binoni, אני כותב / אתה כותב / הוא כותב are the identical word כותב (kotev) and only the pronoun tells them apart. In the past each person has its own ending: כתבתי / כתבת / כתב are three different words. The verb, not the pronoun, now carries “who”.

• The base is the 3ms: the CaCaC pattern. The dictionary/base form is the third-person masculine singular, an “a” after each of the first two radicals: כתב (katav), למד (lamad), שמר (shamar), סגר (sagar, “closed”), גמר (gamar, “finished”). Everything else is built by adding a suffix to this stem.

• Nine person-suffixes — one set for every strong pa’al verb. ־תי (-ti, I), ־ת (-ta, you m.sg), ־ת (-t, you f.sg), — (nothing, he), ־ה (-a, she), ־נו (-nu, we), ־תם (-tem, you m.pl), ־תן (-ten, you f.pl), ־ו (-u, they). Learn these once and they transfer to any strong root.

• Vowel-suffix forms reduce the stem — katav → katva, katvu. Before the vowel-initial endings ־ה (3fs) and ־ו (3cp), the stem’s second “a” drops and the stress moves to the ending: כתב → כתבה (katav → katva), כתב → כתבו (katav → katvu); שמר → שמרה / שמרו (shamar → shamra / shamru). Do not insert an extra vowel — it is katva, never *katava.

• The 2nd-plural forms shift stress and thin the first vowel. כתבתם (ktavtem) and כתבתן (ktavten) put the stress on the suffix, so the first “a” thins to almost nothing: k(a)tavtem. They are a touch formal — very common in writing, less so in casual speech, where people often keep the fuller sound — but the written form is כתבתם / כתבתן.

• The pronoun is now optional. Since the ending encodes the person, כתבתי, למדנו, שמרתי stand alone. The third-person forms (כתב, כתבה, כתבו) are the exception you usually still name — הוא כתב, היא כתבה, הם כתבו — because the bare verb doesn’t tell you which he/she/they.

• A definite object still takes את. Tense changes nothing about object marking (lesson 15): כתבתי את המכתב (katavti et ha-michtav, “I wrote the letter”), היא סגרה את הדלת (hi sagra et ha-delet, “she closed the door”).

• Two forms collide unvocalized — read them by context. With no niqqud, כתבת is both katavta (you m., “you wrote”) and katavt (you f.); likewise למדת = lamadta / lamadt. Only the person you are addressing tells you which. (Don’t confuse these past forms with the present feminine כותבת, kotevet — that one carries a ו.)

Forms & patterns

The full pa’al past on כ־ת־ב (write) — suffix, pronoun, and form:

The same nine suffixes on two more strong roots (ל־מ־ד “learn/study”, ש־מ־ר “guard/keep”):

The reduction, up close — the middle “a” drops before a vowel ending:

Present vs. past: what marks “who” (root כ־ת־ב):

Examples

Common mistakes

• אני כתב את המכתב -> (אני) כתבתי את המכתב (katavti et ha-michtav) - the past shows the subject with a suffix; “I wrote” is כתבתי, and adding אני doesn’t fix the bare 3ms verb.
• הוא כתבה -> הוא כתב (hu katav) - כתבה (katva) is 3f.sg “she wrote”; the 3m.sg “he wrote” is the bare stem כתב (katav).
• היא כתבה (katava) -> היא כתבה (katva) - no extra vowel: the middle “a” drops before ־ה, so katva, not *katava.
• הם כתבו (katavu) -> הם כתבו (katvu) - the same reduction before ־ו: katvu, not *katavu.
• את כתבתָ -> את כתבת (katavt) - to a woman the ending is bare ־ת (katavt); ־תָ (katavta) is the masculine “you wrote”.
• כתבתי המכתב -> כתבתי את המכתב (katavti et ha-michtav) - a definite object still needs את, exactly as in the present; the tense doesn’t change that.
• אתמול אני כותב מכתב -> אתמול כתבתי מכתב (etmol katavti michtav) - a completed past action needs the past; don’t leave it in the present binoni כותב.

Tips

• Memorize the nine suffixes as one block — ־תי, ־ת, ־ת, —, ־ה, ־נו, ־תם, ־תן, ־ו — because they are identical for every strong pa’al verb. Learn the pattern, not each verb.
• Treat the 3m.sg (katav, lamad, shamar) as the peg: it is the bare CaCaC stem, and you build all eight other persons by attaching an ending to it.
• Watch the reduction: before ־ה (she) and ־ו (they) the stem’s second “a” drops — katav → katva / katvu, shamar → shamra / shamru. Never say *katava or *katavu.
• Because the ending already names the subject, drop the pronoun for 1st and 2nd person (כתבתי, למדנו). The third-person forms usually keep הוא / היא / הם, since the verb alone doesn’t say which one.
• Don’t drag present-tense habits across: 1c.sg כתבתי is the same for a man and a woman — the past does not split the 1st person (I, we) by gender the way the binoni does.
• Read the unvocalized collisions by context: כתבת is katavta to a man, katavt to a woman; the sentence and the addressee decide, not the spelling.
• Anchor the past with a time word — אתמול (etmol, “yesterday”), אמש / אתמול בלילה (last night) — so you reflexively switch out of the present.