If - Clauses
http://www.englischservice.de/IF-CLAUS.htm:
Usually we distinguish between three types of if-clauses:
Type I (realistic condition): |
If the weather is nice, we will go for a walk. |
If-clause: simple present main clause: will-future |
Type II (theoretical condition): |
If the weather was nice, we would go for a walk. |
If-clause: simple past main clause: conditional I |
Type III (theoretical condition in the past): |
If the weather had been nice, we would have gone for a walk. |
If-clause: past perfect main clause: conditional II |
Gemäß präskriptiver (normativer) Grammatik darf im Nebensatz nach if (‚wenn', ‚falls') in der Regel bekanntermaßen kein Konditional (would) stehen.
Ausnahmen von der Regel:
Ebenso wichtig für die Korrektur sind jedoch die Ausnahmen von der Regel beim Ausdruck von Wunsch, Bereitschaft, höflicher Bitte, nachhaltiger Aufforderung bzw. Unwillen und Verärgerung. Obwohl diese Fälle im strengen Sinne keine Normabweichungen sind, seien sie im Folgenden noch einmal aufgeführt:
If you would lend me some money, (would lend: korrekt); I would be very grateful to you (polite request!)
If you would let me know shortly, (would let: korrekt); I'd be much obliged to you. polite formula, (reference to
(un)willingness)
If you would agree to our plans, (request: asking for readiness to comply), we could take suitable measure.
If you would only listen, I might convince you (would listen: korrekt; anger at s.o.'s purposefullydoing / not doing s.th.)
If he would only stop smoking, he would recover much sooner (would stop: korrekt; activity verb to express anger, desire)
MERKE: I wouldn't do that if I would be you (would be statt were nicht möglich bei to be
( = state verb)
Erklärung der 3 Typen:
http://www.kico4u.de/english/grammatik/conditionals.html
Übungen:
http://a4esl.org/q/h/vm/if-clauses.html
http://www.english-zone.com/grammar/if-thenpres.html
http://www.english-zone.com/grammar/if-then1.html