Study materials
This paragraph changes tense three times, each time on purpose.
The company was founded in 1998. Since then it has opened offices in four countries. Today it employs six hundred people and is preparing to enter a new market.
History, a summary up to now, the present state, the current stage.
Four forms do four different jobs. This article explains the roles of tenses in a paragraph, the usual tenses of different genres, the news and the details, the historic present, switching tense in a story, and the grammar of the three layers of an academic paragraph.
The roles of tenses in a paragraph
In a connected text each form has its own role.
| Form | Role | Example |
|---|---|---|
| Past Simple | a past event with a known time | was founded in 1998 |
| Present Perfect | a summary from the past up to now | since then it has opened |
| Present Simple | a lasting present state | it employs 600 people |
| Present Continuous | a temporary current stage | it is preparing |
| Past Perfect | a step back from a past event already mentioned | it had tried twice before |
Since then, so far and to date need the Present Perfect, because they cover the time up to now. In 1998, last year and two years ago need the Past Simple, because they name a finished time.
Tense and genre
The same content is usually given in different forms in different genres.
| Genre | Usual form | Why |
|---|---|---|
| summary of a book or film plot | present | the plot exists in the text, not in the past |
| research paper, methods and results | past | you describe what you did and found |
| research paper, conclusions | present | the claim holds now |
| review of earlier studies | Present Perfect | Several studies have shown, that is accumulated knowledge |
| reference to your own text | present | Table 2 shows, Section 3 describes |
| news | Present Perfect, then past | first the news itself, then the details |
These are genre conventions, not strict rules. A plot summary in the past is also grammatically correct, but the present is more usual. What matters is to keep the chosen form to the end.
The news and the details
News is usually given in the present perfect, because it matters now. As soon as the speaker moves on to details, when and how it happened, they use the Past Simple.
Scientists have found water on a distant planet.
The news.
They made the discovery last week with a new telescope.
Details with a time, so the Past Simple.
The present perfect does not go with words of finished time: yesterday, last week, in 2019, when I was a child. These words require the Past Simple.
The historic present
The historic present is the present tense used to tell about the past. It puts the reader inside the scene. It appears in spoken stories and jokes, in sports commentary and in news headlines.
So this man walks into a bar and orders a glass of milk.
The start of a joke.
President visits Lviv
A headline about something that has already happened.
The plot of a book or film is usually retold in the present: In the novel, the narrator loses his job and moves to the coast. People speak the same way about what a text says: The author argues that…, The report says that…
Another present names an act performed by the words themselves. I apologise, I promise, We confirm receipt of your letter. These take the simple form, because saying it is doing it.
Switching tense in a story
A story in the past can move into the present to put the reader inside the scene. This is called the historic present. The switch should be visible, for example at a sentence boundary after words like then one morning, and the new tense is then kept.
In 1943 the city was almost empty. Then one morning a man walks into the square and starts to play.
The switch comes at a sentence boundary.
A switch in the middle of one series of actions, for no reason, reads as a mistake, not as a device.
Three layers
In conversation someone else's claim, your evidence and your conclusion merge. In academic text each layer has its own grammar.
| Layer | Usual grammar | Example |
|---|---|---|
| someone else's claim | a reporting verb | Chen (2021) argues that … |
| your evidence | past tense, specific data | Our logs recorded 14 failures. |
| your conclusion | present tense, often hedged | This suggests that … |
This is a genre convention. The past shows what you did and found, and the present what holds now.
Common mistakes
The first mistake is the Present Perfect with a finished time.
The company has been founded in 1998. → The company was founded in 1998.
In 1998 names a finished time.
The second mistake is the Past Simple after since then.
Since then it opened offices in four countries. → Since then it has opened offices in four countries.
Since then covers the time up to now.
The third mistake is a change of tense in the middle of a series of actions.
She opened the door and sees the letter. → She opened the door and saw the letter.
Two actions in one series take the same tense.
The first and second mistakes show in the time word. A finished time such as in 1998 needs the Past Simple, while since then, so far and to date need the Present Perfect. The third shows between verbs joined by and. If they describe one series of actions, they take the same tense.