grammar - More complex comparisons with より

The use of より/のほうが for comparisons seems straightforward when comparing like with like (e.g. "私の方が彼より英語が上手く話せる"). But I have trouble finding a non-clumsy way to express more complex comparisons, e.g. constructing as phrase like "a person who speaks English better than I speak Japanese".

What are some natural ways of expressing this kind of comparison, where we're not directly comparing the same quality/attribute between the two sides?

Answer

より can take a subordinate clause, just as in English "than" can take a subordinate clause. So literal translations would be:

私が日本語を話すより彼は英語が上手く話せる。
私が日本語を話すより彼の方が英語が上手く話せる。
彼の方が私が日本語を話すより英語が上手く話せる。
He speaks English better than I speak Japanese.

The third one is nested and may seem complicated, but is closer to your original sentence.

Or using a relative clause, this becomes:

私が日本語を話すより英語が上手く話せる人
a person who speaks English better than I speak Japanese

In the above examples, 英語が話せる and 英語を話せる are basically interchangeable.

But I'd suggest you rephrase it and say the same thing more simply:

彼の英語の方が私の日本語より上手い。
私の日本語より彼の英語は上手い。
His English is better than my Japanese.

私の日本語より英語が上手い人
a person whose English is better than my Japanese