How to express the subjunctive mood in Japanese

Question

I recently learned the Vばよかった construction, which roughly means "it would be better had I done V". This got me curious about how to construct a sentence in subjunctive mood in Japanese, or even if it is possible to do so.

After some googling, I found that there are three types of subjunctive mood in English, depending on whether the action happens in the past, present or future. Here are three example sentences, one for each tense.

Present: If places were alike, there would be little need for geographers.

Past: If he had known your phone number yesterday, he would have called you.

Future: If he were to leave today, he would get there by Friday.

It seems that the ばよかった form is a narrow type of the past subjunctive mood.

So I guess my question is twofold:

1. How to translate those three sentences into Japanese?

2. What Japanese grammar is equivalent to the subjunctive mood? Do there exist separate grammar forms for each tense?

Edit. I found this article online: http://ezproxy.lib.hit-u.ac.jp/rs/bitstream/10086/27040/1/HJart0550100450.pdf

This seems to be exactly I need, but it is very long and academic, so it is difficult to go through. Also it is written in rōmaji only. I will try to go through it tomorrow. In the mean time, someone please provide a succinct explanation.

Edit 2: According to my understanding so far, apparently there is no special grammatical construction in Japanese that corresponds to the subjunctive mood in English, the way to express counterfactual meaning is simply the if construction (ba/nara/tara/to), with time of action indicated by the tense of the verb.

Answer 1

There is no special grammatical construction to show this "mood" in Japanese. You can just use normal conditional sentences using ～ば, ～たら or ～なら, optionally with もし or もしも. That said, there are several words that are often used to show the feelings of subjunctive mood in English:

• ～(の)に or ～(のだ)が/けど is often used to show your regret or disappointment. See: 「たら〜のに」Grammar help!
• 仮に, 仮の話として, もしもの話として and so on are used to explicitly show your if-clause is an unlikely hypothesis. You don't usually need this, but you may be able to avoid offending someone if used properly.

Your examples are translated like so:

If places were alike, there would be little need for geographers.
仮に土地が(みんな)同じようなものであるなら、地理学者はほぼ必要ないだろう。

If he had known your phone number yesterday, he would have called you.
昨日電話番号を知っていたら、彼は君に電話したでしょう(に)。 _{(use に to show disappointment)}

If he were to leave today, he would get there by Friday.
もし今日出発すれば、金曜日にはそこに着くでしょう。