Type 2 conditionals- IF+ PAST SIMPLE ( if-clause) main clause - WOULD / COULD/ MIGHT+ BARE INFINITIVE
exp: IF i HAD a lot of money, i WOULD BUY a house in Monte Carlo .
Type 3 - IF+ PAST PERFECT ( clause) - main clause - WOULD/ COULD /MIGHT +HAVE + PAST PARTICIPLE
exp: IF i HAD KNOWN that Stanley was in town , i WOULD HAVE INVITED him to my party