When learning Japanese, it’s common to run into lesson prefaces that say things like, This is really different from how it works in English, so here’s what’s going on. Then they proceed to explain something that is not all that different from a perfectly understandable English analog.
One such case is future tense. Japanese learners are bound to run into statements like this:
Indeed, in Japanese, there is no future tense. The present tense is used to express both present and future actions, and context or the presence of certain other words in a sentence (especially those relating to time) indicate when something is in the future.
ジョンさんは コンビニに 行く (jonsan wa conbini ni iku) means “John goes to the convenience store,” with pretty much the same meaning as in English. But 明日ジョンさんは コンビニに 行く means “John will go to the convenience store tomorrow.” No change in the verb—we’ve just added the word 明日 (ashita - tomorrow), and now it’s understood as an action in the future.
There are two problems with statements like the one I screenshotted. First, we do the exact same thing in English with the present futurate.
The present futurate is the use of the present tense plus a time word to indicate an action in the future. There’s a limitation around the use of the present futurate in English: Generally it’s only permissible for things that are currently known. It’s used for cyclical patterns in nature, or for scheduled events. It also commonly appears in conditionals. Here are some examples with comments.
The Blackburn Rovers play against Oxford United next Monday. | Scheduled events are considered to be known, even though they could be canceled. |
Pumpkin spice latte season arrives soon. | Cyclical events like the change of seasons or the procession of the day are considered to be known. Random events like rain are not, even if they’ve been forecast. |
If you don’t get back to your desk, you’re fired. | Only said by someone with the ability to fire you, thereby turning it into a threat. Not used by someone who can’t fire you to make a likely but uncertain prediction of consequences. For that you would have to use will/might get/be fired. |
If I want to pay, do I go up to the counter, or wait for the bill? | The constraint is more relaxed when used in a question, but it’s typically used for repeatable occurrences. |
For Japanese, when students ask questions like, How do I know if something is intended as present or future? the correct response is, The same way you know how to interpret the English sentence, “My uncle’s plane arrives at 6:30.”
The only difference is that Japanese doesn’t have the knowledge constraint. In English, it would be odd to say It rains tomorrow instead of It will rain or It’s going to rain. But in Japanese, it’s fine: 明日は雨が降ります = literally It rains tomorrow, but It will rain tomorrow in translation. It should be obvious that, when you drop the present knowledge constraint, will becomes a lot less important for talking about the future.
Which brings us back to the second problem with the statement I screenshotted: English doesn’t have a future tense. English talks about the future a dozen different ways without will, and will is far more complicated than acting as a future marker. It’s better understood as part of our mood system than our tense system. But that’s a much more technical topic concerning how English is taught, rather than an issue with Japanese instruction, so that will have to be its own post.