Which conditional?

[Minona]

Test No. errors/inter-9 "Conditionals", question 1

If I win the lottery, I should buy you a very big car as a present.

(a) If
(b) win
(c) should

Test No. errors/inter-9 "Conditionals", answer 1

If I win the lottery, I will buy you a very big car as a present.

Correct entry: will
The error was: (c) should
_________________________

what coditional is it?

[Torsten]

Conditional I

TOEIC listening, talks: Informing city residents about an Independence Day parade