A sentence that does not seem right on the count of syntax

• Not only are verbs largely uninflected in English, but also nouns, pronouns and adjectives.

This sentence seems very unusual although it is understandable. I can't tell what is wrong with it, if anything is. Possibly the adverb "only" is not properly positioned but I can't assert that.

Would someone confirm that there is a problem and explain what is wrong? Otherwise, can someone show that there is no problem?

A sentence that does not seem right on account of syntax

• Not only are verbs largely uninflected in English, but also nouns, pronouns and adjectives.

This sentence seems very unusual although it is understandable. I can't tell what is wrong with it, if anything is. Possibly the adverb "only" is not properly positioned but I can't assert that.

Would someone confirm that there is a problem and explain what is wrong? Otherwise, can someone show that there is no problem?