it (is)

Writers often mix third-person singular present (VBZ: he runs) with simple past (VBD: he ran). That swap changes time and meaning, and it appears often in workplace, school, and casual writing.

Use quick checks, simple memory tricks, and ready-to-copy rewrites below to spot and fix VBZ/VBD mistakes fast.

Quick answer: When to use VBZ vs VBD

VBZ = third-person singular present (he/she/it + verb+s). VBD = simple past (regular verbs add -ed; many common verbs are irregular). Use VBZ for habitual or current actions; use VBD for completed past actions.

VBZ: he runs, the report shows, the server crashes (habit or present).
VBD: he ran, the report showed, the server crashed (completed past).
Past time markers (yesterday, last week, in 2019) point to VBD; present markers (now, every day, usually) point to VBZ.

Core explanation (short rules)

Use VBZ with third-person singular subjects (he, she, it, or singular nouns) for present or habitual actions. Add -s or -es: 'writes', 'fixes', 'goes'.

Use VBD for actions completed in the past. Regular verbs add -ed (work → worked); many verbs are irregular (go → went, run → ran).

Match the verb form to the time you mean, not to a nearby word that sounds similar.
Perfect tenses use auxiliaries (has/have/had) with the past participle (has run, had run) - these are different from simple past forms.
Modals (can/could, will/would) alter meaning and don't form VBD by adding -ed.

Present: She writes reports every week. (VBZ - habitual present)
Past: She wrote the report yesterday. (VBD - completed past)

Common patterns that cause VBZ/VBD mistakes

Errors pop up when the subject is distant from the verb, a time phrase conflicts with the verb, or writers shift tense while reporting speech.

Intervening clauses: Re-identify the subject after commas or parentheticals before choosing the verb.
Reporting verbs: Decide whether reporting is present or past: "He says he left" vs "He said he left."
Tense hopping: Avoid switching present and past within a paragraph unless the change is intentional and clear.

Wrong → Right: Wrong: 'She runs the meeting yesterday.' →
Right: 'She ran the meeting yesterday.'
Wrong → Right: Wrong: 'My teammate say the data was wrong.' →
Right: 'My teammate said the data were/was wrong.' (match plurality)
Wrong → Right: Wrong: 'The committee believes the project needed more resources.' →
Right: 'The committee believed the project needed more resources.' (shift reporting tense)

Real usage and tone: when tense choice changes meaning

Present tense (VBZ) signals current relevance or general truths: 'This study shows...'. Past tense (VBD) reports events that occurred: 'The study showed...'. Choose based on whether the finding is ongoing or a finished event.

Research: methods/results typically use past; established facts and paper claims often use present.
News: present for live commentary, past for reported events.
Narrative: the historical present is a deliberate stylistic choice, not an accidental tense shift.

Present (ongoing): The survey shows employees prefer remote days.
Past (specific): The survey showed employees preferred remote days in 2020.
Stylistic (intentional): He walks into the room and everyone gasps. (historical present)

Memory tricks and quick checks

Three quick checks: 1) Find time words (yesterday/now). 2) Identify the subject (is it third-person singular?). 3) Ask: is the action completed? Those answers point to VBZ or VBD.

Underline the subject, circle time words, then choose present or past.
If you see 'yesterday/last week/in 2019', pick past (VBD).
If you see 'every day/now/usually', use VBZ for third-person singular.

Mnemonic: S-P-T - Subject → Present? → Time. If Subject = 3rd sing and Time indicates present, pick VBZ.
Test with aux: Try does/did: 'Does he run?' → present; 'Did he run?' → past. Then swap to 'runs' or 'ran'.

Try your own sentence

Test the whole sentence in context. The surrounding words usually make the correct tense clear.

How to fix your sentence: quick rewrites (copy-paste fixes)

Read the sentence, decide the intended time frame, then replace the verb. After fixing one verb, scan the paragraph for other verbs that must change with it.

When unsure, add a time word like 'yesterday' to force the correct past form.
Keep edits minimal for chat or email: swap the verb form rather than rewording the whole sentence.

Rewrite:
Original: 'Our manager say the deadline was moved.' → Fix: 'Our manager said the deadline was moved.' (shift reporting verb to past)
Rewrite:
Original: 'Each team member submits their draft last Friday, but only John submits his.' → Fix: 'Each team member submitted their draft last Friday, but only John submitted his.' (make completed actions past)
Rewrite:
Original: 'The server crash every morning last month.' → Fix: 'The server crashed every morning last month.' (past habitual → VBD)

Examples: compact wrong/right pairs and casual fixes

Six frequent wrong/right pairs plus three casual examples. Focus on patterns rather than memorizing every verb.

Pair1: Wrong: 'He runs the analysis last week.' →
Right: 'He ran the analysis last week.'
Pair2: Wrong: 'The report says the server crashed at midnight, but it restart this morning.' →
Right: 'The report says the server crashed at midnight, but it restarted this morning.'
Pair3: Wrong: 'She eats sushi at the conference last year.' →
Right: 'She ate sushi at the conference last year.'
Pair4: Wrong: 'The team agrees on the strategy yesterday.' →
Right: 'The team agreed on the strategy yesterday.'
Pair5: Wrong: 'My colleague say the client prefers a June launch.' →
Right: 'My colleague said the client preferred a June launch.'
Pair6: Wrong: 'It seems like he left early, but he was here at noon.' →
Right: 'It seemed like he left early, but he was here at noon.' (match reporting time)
Casual1: Wrong: 'He always forget his keys last week.' → Right options: 'He always forgot his keys last week.' OR 'He always forgets his keys.'
Casual2: Wrong: 'She says she left the party early, but she still show up at noon.' →
Right: 'She said she left the party early, but she still showed up at noon.'
Casual3: Wrong: 'I thinks we met last month, right?' →
Right: 'I think we met last month, right?' OR 'I thought we met last month, right?'

Work and school mini-collections (ready-to-use sentences)

Set tense consistently by section: results/methods → past; policy/ongoing status → present. When converting notes into a report, choose the tense for each section before adding details.

Work1: Wrong: 'The sales team reports strong quarter, but revenue drop in April.' →
Right: 'The sales team reported a strong quarter, but revenue dropped in April.'
Work2: Wrong: 'Our manager say the new policy apply to all departments.' →
Right: 'Our manager said the new policy applied to all departments.'
Work3: Wrong: 'The software crashes every time we run that report last month.' →
Right: 'The software crashed every time we ran that report last month.'
School1: Wrong: 'The experiment shows that the compound reacted, so we conclude it is unstable.' →
Right: 'The experiment showed that the compound reacted, so we conclude it is unstable.'
School2: Wrong: 'She write in her analysis that temperature increase the yield last semester.' →
Right: 'She wrote in her analysis that temperature increased the yield last semester.'
School3: Wrong: 'Each student submits their assignment yesterday but one forget.' →
Right: 'Each student submitted their assignment yesterday, but one forgot.'

Mechanics: hyphenation, spacing, punctuation, and brief grammar checks

Hyphens and spacing don't change tense, but punctuation and interrupts can hide the subject and lead to the wrong verb. Re-identify the subject after commas or parentheticals.

Commas can separate the real subject: 'The head of the department, along with two assistants, was at the meeting.' - the verb remains singular.
Fragments and missing auxiliaries cause errors: 'She go yesterday' → fix to 'She went yesterday' or 'Did she go yesterday?'
Spacing or hyphenation issues don't affect tense - focus on verb form and time markers.

Punctuation: Wrong: 'The head of the department, along with two assistants, were at the meeting.' →
Right: '...was at the meeting.'
Auxiliary: Wrong: 'You finish that?' →
Right: 'Did you finish that?' (use 'did' for past questions)

FAQ

How do I decide between 'runs' and 'ran' quickly?

Ask whether the action happened in the past (use 'ran') or is happening now/regularly (use 'runs'). Look for time markers like 'yesterday' (past) or 'every day' (present).

Can I mix present and past in the same paragraph?

Only when the shift is intentional and clearly indicated (e.g., background in past, current interpretation in present). Otherwise keep the paragraph consistent.

What about collective nouns: 'the team agrees' or 'the team agree'?

In American English, collective nouns are usually singular: 'the team agrees.' British English may use plural when emphasizing individual members: 'the team agree.' Be consistent with your dialect.

Will grammar checkers catch VBZ/VBD errors for me?

Many checkers catch common VBZ/VBD mismatches and suggest fixes. Always read the explanation to confirm the intended time frame before accepting changes.

Any fast habit to avoid repeating these errors?

Edit three sentences per day: underline the subject, circle time words, and confirm auxiliaries. That checklist builds awareness quickly.

Need help fixing a sentence now?

Paste one tricky sentence into a checker or ask a colleague for a quick sanity check. Paste three sentences here if you want immediate rewrite suggestions focused on VBZ vs VBD.