Usage of ameliorate

The other day I have a conversation with a Professor of English. She asked me:

Why do you attend this course?

I replied:

I want to ameliorate my pronunciation.

She corrected me and suggest that I use improve instead. She told me that ameliorate is considered very formal. Is she right?

Ameliorate is a less common word than improve, so I'd agree that it sounds more formal and could be out of place in everyday conversation. Putting that aside, it also sounds like a slightly odd usage of the word - while ameliorate does mean to improve, it's generally used more as a synonym of resolve, which is to fix a specific problem, rather than to generally improve the quality of something.

One might take medicine to ameliorate their flu symptoms, but one does not practice piano to ameliorate their playing. From the context of your sentence, it's clear that you want to improve your pronunciation, but it sounds odd with ameliorate since "pronunciation" alone does not have any inherent negative connotation. Saying "I want to ameliorate my poor pronunciation" sounds a bit more natural, since there's a clear negative that you're attempting to fix/ameliorate. Either way, improve is the simpler and more conversational choice here.

Yes, I share the professor's preference.

When I asked Google Books for a few examples of each word, here's what I got for ameliorate:

• Strategies to Ameliorate Oxidative Stress During Assisted Reproduction
• Use of Vegetation to Ameliorate Building Microclimates
• Ameliorate the Burden of Preprocessing by Pre Model Workflow

And here's what I got for improve:

• How to Improve at Soccer
• 100 Ways to Improve Your Writing
• Improve Your Communication Skills

I think you can see there the association of ameliorate with a more technical context, and the word improve with a more everyday context.

Also, improve seems to be a lot more common than ameliorate.

But what's more, ameliorate has a sort of funny flavor here. Merriam-Webster says that the word "implies making more tolerable or acceptable conditions that are hard to endure." Unless your accent is really something special, ameliorate seems like a strange word to use here.