giving the user choice over “Did you mean?”
Be really really wary of expanding the users queries without telling them. Don’t just give them results for aubergine and results for eggplant, when they only searched for Aubergine. You think you are being clever and helpful. If you’re wrong about the expansion then you are just being extremely irritating.
Either:
a) Suggest the expansion but don’t run it for them. Risks them missing it.
b) Run the expansion but tell them you’ve done it. Still risks them missing it.
Google’s experimenting with both approaches over the years. And currently has a bit of a mixed approach. Don’t assume their approach has “cracked” the problem.