Best correction: "Crows would love to eat the harvest if it weren't for the scarecrow."
Or a simpler way to say it: "The scarecrow keeps the crows away, so they can't eat the harvest."
- What "but for" means: "But for" is like saying "except for" or "if it weren't for."
- Why we change it: The original is a bit old-fashioned. Saying "if it weren't for the scarecrow" sounds clearer.
- Little tip: Put a period at the end of the sentence: it finishes the thought.
Pick the one you like best — both say the same thing: the scarecrow stops the crows from eating the harvest.