Question

Conditional clause
I assure if i ______(Know) you were ill, i _____(meet) you at the hospital.

Answer 1

1.had known
2.would have met

Answer 2

The answer is “I assure if I knew you were ill, I would have met you at the hospital”.  

Here THE conditional clause is “I assure if I knew you were ill”.

Here a condition has been declared, and the rest part of the sentence large depends on this condition.

Unless the condition is met, there is uncertainty of the action, hence it is called the conditional clause.