If I had studied medicine, I would be a doctor now.
Standard conditionals stay in one time. A mixed conditional links an unreal moment in one time to a result in another.
If I had saved more, I would own a house now.
If he weren't shy, he would have spoken up.
past → present
present → past
The if-clause and the result clause point at different times.
If + past perfect, ... would + base verb (now)
If + past simple, ... would have + past participle (then)
Ask: when is the condition? When is the result?
If I would have known, I would be there now.
Correct: If I had known, I would be there now.
If she were more careful, she wouldn't lost her keys.
Correct: she wouldn't have lost her keys.
If he had trained, he will be fit now.
Correct: he would be fit now.
If they weren't lazy, they would have finish it.
Correct: they would have finished it.
Say the answer out loud — then tap to check.
If I had takenA that job, I would have beenB much happier todayC, butD I turned it down.
BI would have been → I would be
✓ past condition + present result → would + base verb
If he had listenedA to the doctor, he would beB healthier now, butC his habits wasD always terrible.
Dhis habits was → his habits were
✓ his habits is plural → were
If I would have savedA more money, I would ownB an apartment byC now insteadD of renting.
AIf I would have saved → If I had saved
✓ no would have in the if-clause
Use a mixed conditional in every answer.
Never put "would have" in the if-clause.