Sense in Verb Tense

I have been trying to learn Finnish for more than a quarter of a century. It is a difficult language for English speakers to learn, so I haven't made much progress, but I'm still trying. One thing I have found very interesting is that while Finnish does have forms of verbs in past tense and present tense, it doesn't have a future tense. The way they indicate that something will be happening in the future is by using the present tense form of the verb and then saying when it will be happening (or if the time is unknown, there are other ways to say that it will be happening at some point in the future).
If I were to apply that way of speaking to English, and wanted to say, "I will do that tomorrow," I would instead say something like, "Tomorrow, I am doing that." Although these sentences mean very close to the same thing, they do have subtle differences related to intention. If I could speak Finnish, I would tell you if Finnish speakers have other ways to indicate intention, but I'm willing to guess that they do.
In English, there are twelve tenses that can be used with every verb. English has past, present, and future tenses for each of four categories: simple, perfect, continuous (also called progressive), and continuous perfect (also called progressive perfect).
Here is an example of a sentence with the verb "eat" in each form.
- I eat sushi. (simple present tense)
- I ate sushi. (simple past tense)
- I will eat sushi. (simple future tense)
- I have eaten sushi. (perfect present tense)
- I had eaten sushi. (perfect past tense)
- I will eat sushi. (perfect future tense)
- I am eating sushi. (continuous/progressive present tense)
- I was eating sushi. (continuous/progressive past tense)
- I will be eating sushi. (continuous/progressive future tense)
- I have been eating sushi. (continuous/progressive perfect present tense)
- I had been eating sushi. (continuous/progressive perfect past tense)
- I will have been eating sushi. (continuous/progressive perfect future tense)
At this point you might be asking why we need this many different ways to say that sushi is/was/will be eaten by me. Well, the simple forms are just the basic way to say it. If I want the reader to know that I have finished the action of eating sushi, then I would use perfect tense. Another thing about perfect tense is that it often has some kind of timeframe attached to it. An example of this with perfect present tense is, "I have eaten sushi two days in a row before (but only because one of the days was my birthday)."
If the sushi eating is still happening (is this Heaven?!), we would use continuous/progressive tense. These verbs usually end in "ing," but not always. If the sushi eating was ongoing, but has now ended, I would use continuous/progressive perfect tense. Again, because this is a form of perfect tense, there is often a timeframe included in the sentence. An example with continuous/progressive perfect present tense would be, "I have been eating sushi since I was 38 years old."
All of these different ways of using one verb give us the opportunity to be precise about what we want to say.
Sometimes writers will switch from one tense to another without realizing it, which can feel messy to the reader. Unless there is purpose in switching tenses, the flow will be better if there is consistency.
Examples of tense switching appear below:
- I saw the dragons and cannot move. ("I see the dragons and cannot move" or "I saw the dragons and could not move" are better.)
- I see the dragons and cannot move. Then, I ran for my life and searched for cover. ("I see the dragons and cannot move. Then, I run for my life and search for cover." If I want to indicate that this search is ongoing, I can say "searching for cover" instead of "and search for cover." Another option is to put it all in past tense: "I saw the dragons and could not move. Then, I ran for my life and searched for cover.")
Even though the initial examples make sense, they sound better when the tense stays the same within the sentence and between the sentences. Tense changes do happen in writing. We rarely stay only in the past or the present without ever speaking of the future. However, good writers switch tense on purpose, not by accident.