1. indirect/reported speech
present -> past
present perfect -> past perfect
past perfect -> past perfect
past -> past perfect
present progressive -> past progressive
past progressive -> past perfect progressive
future: will -> would; may -> might, shall -> sould; can -> could
personal pronouns: I -> he, she
possessive pronouns: my -> his, her
time phrases: yesterday -> the day before; tomorrow -> the next day
say, claim, explain, tell, speak, answer, report, read, believe, respond, reply,
regret, admit, cry, shout, ask
I: if + infinitive + will + infinitive
condition can be fulfilled
eg: If I have the money I will buy the house.
Wenn ich Geld habe, kaufe ich das Haus.
II: if + past participle + would + infinitive
condition could be fulfilled, but unsure
eg: If I had the money I would buy the house.
Wenn ich Geld hätte, würde ich das Haus kaufen.
III: if + had + past participle + would + have + past participle
condition cannot be fulfilled
eg: If I had had the money I would have bought the house.
Wenn ich Geld gehabt hätte, hätte ich das Haus gekauft.