✍️ English & Grammar · Chapter 2

Tenses that actually cause errors

English has twelve tenses. Four of them cause almost every mistake a working professional makes.

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The basics

A tense is the verb form that tells the reader when something happened and whether it is finished: I deployed (done, at a definite time), I have deployed (done, and it matters now), it has been failing (started earlier, still happening).

The problem it solves: in professional writing, tense carries status. "The job was failing" tells on-call it's over; "the job has been failing" tells them it's still broken. Choose the wrong one and a reader acts on the wrong fact.

The mental model: the time expression picks the tense. Find words like yesterday, since Monday, already, right now first, and the verb follows. A finished, stated time (yesterday, last week, ago) closes the box → simple past. A period that reaches the present (since, for … and still) → present perfect. Two past events → past perfect for the earlier one.

Explained

~~I have completed the migration yesterday.~~

I completed the migration yesterday.

~~I am having a doubt about the schema.~~

I have a question about the schema.

~~The job was failing since Monday.~~

The job has been failing since Monday.

Three of the most common errors in Indian professional English, and each is a single rule. Learn those rules and the other eight tenses look after themselves.

Three kinds of photograph

Simple past is a photograph with a date written on the back. I deployed it on Tuesday. Finished, dated, closed.

Present perfect is a photograph of a path leading to where you are standing. I have deployed it. When? Doesn't matter — the point is the situation now: it's out there.

Past perfect is a photograph of an earlier photograph. The consumer had already committed the offsets when it crashed. It says one past thing happened before another past thing.

The most common error is using the path photograph while pointing at a date. The moment you say yesterday, last week, in 2024, you have closed the box — and a closed box takes simple past.

Rule 1 — present perfect never takes a finished time

This is the single highest-value rule in the lesson.

| Time expression | Tense | | --- | --- | | yesterday, last week, in March, at 3pm, ago | simple past | | already, just, yet, so far, recently, ever, never | present perfect | | since Monday, for two hours (still true now) | present perfect |

✗ I have submitted the report yesterday.
✓ I submitted the report yesterday.
✓ I have submitted the report.          (when is not the point)
✓ I have already submitted the report.

The test: if you could ask "when exactly?" and the sentence already answers it, use simple past.

One genuinely useful distinction hides in here:

I worked at Infosys. — I don't any more.

I have worked at Infosys. — at some point, possibly still relevant, possibly still there.

On a CV that difference is not decorative. It tells the reader whether the job is current.

Step through a timeline

Five sentences, five tenses, and every one carries information a reader needs: what finished, what came first, what is still going on.

Rule 2 — states don't take the continuous

Some verbs describe states, not actions. States are already ongoing, so putting them in the continuous is like saying "I am owning a car".

Stative verbs: have (possess), know, understand, believe, want, need, like, prefer, seem, mean, own, contain, consist.

✗ I am having a doubt.          ✓ I have a question.
✗ I am not understanding this.  ✓ I don't understand this.
✗ I am knowing the answer.      ✓ I know the answer.
✗ This is containing nulls.     ✓ This contains nulls.

The exception that confuses everyone: have is stative when it means possess, and active when it means do or experience.

✓ I am having lunch.        (doing)
✓ We are having problems.   (experiencing)
✗ I am having a laptop.     (possessing → 'I have a laptop')

Also: prefer question to doubt. A doubt is uncertainty about something you were told; a question is something you want to know. "I have a doubt" reads to many readers as "I don't believe you".

Choose the tense

1. The pipeline ___ (failed / has failed) three times since Monday.
2. I ___ (finished / have finished) the review yesterday.
3. By the time we checked, the consumer ___ (crashed / had crashed).
4. She ___ (works / has been working) here for six years.
5. We ___ (are discussing / discuss) the design right now.
6. I ___ (am having / have) a question about the schema.

When a tense hides whether it's fixed

Two updates in an incident channel, five minutes apart:

"The consumer was failing to commit offsets."

"The consumer has been failing to commit offsets."

The first says it happened and is over. The second says it is still happening right now.

On-call reads the first and stands down. The second would have kept them on the call.

This is the practical case for caring about tense: in operational writing it is not style, it is status. Was it fixed, is it ongoing, did it happen before or after the deploy — every one of those is carried by a tense, and getting it wrong sends someone to bed during an outage.

Same reason past perfect matters in a postmortem: "the config had been changed when the job started" establishes an order of events that "was changed" leaves ambiguous.

Find the time expression first — it picks the tense for you.

A finished time (yesterday, last week) → simple past, never present perfect.

States (have, know, understand) → no continuous.

Words to know

In two minutes

• Four tenses cause almost every professional error: simple past, present perfect, past perfect and the continuous forms.
• Find the time expression first — it decides the tense.
• A stated finished time (yesterday, last week, ago, in 2024) forbids the present perfect: 'I completed it yesterday.'
• 'Since' and 'for … (still true)' need the present perfect: 'It has been failing since Monday.'
• Past perfect marks the earlier of two past events, which is what makes a postmortem's sequence unambiguous.
• Stative verbs (have = own, know, understand, need) take no continuous: 'I have a question', not 'I am having a doubt'.
• In incident updates and CVs, tense is status: ongoing vs resolved, current role vs past role.

Test yourself

There are 8 questions, 3 puzzles and 7 recall cards for this lesson in the app — the recall cards come back on later days, just before you would forget.