Future less vivid
Present subjunctive in both Protasis and Apodosis.
“should” in Protasis, “would” in Apodosis.
Present contrary-to-fact
Imperfect subjunctive in both Protasis and Apodosis.
“were” in Protasis, “would” in Apodosis.
Past contrary-to-fact
Pluperfect subjunctive in both Protasis and Apodosis.
“had” in Protasis, “would have” in Apodosis.
Mixed future
Present subjunctive in Protasis, future indicative in Apodosis.
“should” in Protasis, “will” in Apodosis.
Mixed contrary-to-fact
Pluperfect subjunctive in Protasis, Imperfect subjunctive in Apodosis.
“had” in Protasis, “would” in Apodosis.