回复：I prefer gardening than reading

Thanks a lot. I have learned from this.

I have googled "prefer..to" and "prefer..than",
for example,
I prefer coffee to chocolate.
I prefer to have coffee than to have chocolate.
I prefer having coffee than having chocolate.
I prefer English lessons RATHER than Spanish one.

There are all ok.

But "Prefer ... to" generally sounds better than "prefer ... than".
If I used "prefer" with "than", I'd use "rather than".

Just my two cents.