Can I say 「もしアイスクリームを食べたら、お腹が痛くなったでしょう。」 to mean the third conditional in Japanese

Question

So I know about the fact that Japanese doesn't have a literal equivalent to the third conditional of english.

But to say:

If I had eaten ice cream, my stomach would have hurt.

Can I say it in japanese as:

もしアイスクリームを食べたら、お腹が痛くなったでしょう。

And can I say "If I had come to Japan, I would have stayed in a hotel" as

もし日本へ行ったら、ホテルに泊まりましたでしょう。

Answer 1

This type of conditional is usually translated using -ていれば or -ていたなら. The result part can be in either -ただろう/-たでしょう or -ていただろう/-ていたでしょう.

If I had eaten ice cream, my stomach would have hurt.
もしアイスクリームを食べていれば、お腹が痛くなっていただろう。
もしアイスクリームを食べていたなら、お腹が痛くなっただろう。

If I had come to Japan, I would have stayed in a hotel.
もし日本へ行っていたなら、ホテルに泊まっていたでしょう。
もし日本へ行っていれば、ホテルに泊まったでしょう。

のに is very commonly used with this type of conditional when the speaker is regretting. If the same person wanted to stay in a Japanese hotel for some reason but couldn't, the sentence would be:

If I had come to Japan, I would have stayed in a hotel!
もし日本へ行っていれば、ホテルに泊まったのに！

See also:

• why they used -ていれば instead of -ば?
• ～ば vs ～ていれば in counterfactual conditionals
• Past Unreal Conditional

Lastly, don't use ましたでしょう. This duplication of polite forms is unnatural.