Here is a worksheet on the use of the conjunctions if and whether in both casual speech and formal prose. The distinction, as Professor Paul Brians points out (this and all other materials under the heading above are based on his book Common Errors in English Usage, to which he allows access at no charge at the Washington State University website) is stylistic. Anyway, this is a full-page worksheet with ten sentences for analysis.
But, like practically everything on this blog, this document is formatted in Microsoft Word. You can do what you want with it–it is, as I believe the term of art has it, open source.
If you find typos in this document, I would appreciate a notification. And, as always, if you find this material useful in your practice, I would be grateful to hear what you think of it. I seek your peer review.