Past Tense of “be”
The past tense of be is was/were; the past participle is been.
Why “be” behaves this way
"Be" is the single most irregular verb in English because it isn't really one verb historically — it's a fusion of at least three separate Old English/Proto-Germanic verb roots that speakers gradually welded into one paradigm. The infinitive "be" and participle "been" descend from one root (related to a Proto-Indo-European root meaning "to grow" or "to become," also seen in Latin fui); the present forms "am/is/are" descend from a completely different root (the one behind Latin "esse" and Sanskrit "asmi"); and the past forms "was/were" come from yet a third root, historically meaning something closer to "to remain" or "to dwell" (related to the German verb "war," and distantly to "were-wolf," literally "man-wolf," showing that root's older sense of "man" or "being"). No other verb in English draws its forms from three unrelated sources like this; linguists call this pattern "suppletion," and "be" is the most extreme suppletive verb in the language.
"Be" also holds the record for most surviving distinct forms of any English verb: am, is, are, was, were, be, being, and been — eight forms where a regular verb has only four (walk, walks, walked, walking). Old English distinguished even more forms than modern English does, including separate singular and plural subjunctive forms; the modern eight-form system is already a simplification of a once-larger paradigm, even though it still looks maximally complicated next to every other English verb. This is also why children learning English as a first language acquire "be" forms notably later and more unevenly than regular verbs — there's no single pattern to generalize from.
The common confusion
The confusion with "be" isn't really about which form is correct — most speakers get was/were right by instinct — it's that "was" and "were" split by grammatical number and by mood: "I was" but "we were"; and in the subjunctive, "were" appears even with a singular subject ("if I were you," not "if I was you"), a genuine grammatical distinction rather than an error, covered in full on the subjunctive-mood rule page.
How it's actually used
"Be" is also the only English verb that still shows subject-verb agreement across three distinct present-tense forms (am/is/are) rather than the usual two (base form vs. -s form that every other verb uses). Because it carries so much of the grammar's structural weight — forming every progressive tense ("is running"), every passive sentence ("was written"), and the subjunctive — mastering its irregular forms tends to matter more for fluent-sounding English than any other single verb on this list, which is also why it's typically the very first irregular verb taught in ESL classrooms.
Across the tense system
Across the full tense system, "be" does double duty as both a main verb and the auxiliary behind every progressive and passive sentence: "I am reading" (present progressive), "I was reading" (past progressive), "the letter was written" (passive), "the letter is being written" (passive progressive). No other English verb appears in as many different grammatical roles simultaneously, which is part of why mastering its was/were/been forms has outsized value for overall fluency compared to any other irregular verb.
Common real mistakes
Two real errors show up constantly in writing: dropping the auxiliary entirely in casual dialogue transcription ("you tired?" for "are you tired?"), which is fine in informal speech but flagged in formal writing; and subject-verb agreement slips with collective nouns ("the team are" in British English vs. "the team is" in American English), which isn't a mistake in either dialect but looks wrong to readers of the other one.
Examples
- I was tired after the flight, but my kids were wide awake.
- If I were in charge, the meeting would have been shorter.
- They have been friends since childhood.
- She was the last one to arrive.
- We were about to leave when the phone rang.
- It has been a long week for everyone.
- It is what it is.
- She will be arriving shortly.
Memory trick
Remember the split by number, not by logic: one person "was," more than one person "were" — and if the sentence is a wish or hypothetical ("if I were..."), it's always "were," no matter how many people you're talking about. If you can mentally swap in "if I were a bird," the same "were" rule applies to every other subjunctive sentence.