Ohne Titel

third conditional

serves to express actions in the past that are now impossible to perform

condition (past perfect):

if + pron + had + verb

form of

result (modal+present p):

pron + modal + have + verb

modal:

would, could or should

example:

If I had set my alarm I would have gone for a run

the same example reversed:

I would have gone for a run if I had set my alarm