How do you say "much better" in Mandarin?
好多了 means &quot; much better&quot; Your sentence would be:

&quot;Why not Australia? It's much better than America&quot;
為什麼不是澳大利亞？ 它比美國好多了“

For &quot; so much better&quot; the translation would be &quot;好太多了&quot;

&quot;Why not Australia? It's so much better than America&quot;
為什麼不是澳大利亞？ 它比美國好太多了“

Another way to translate &quot;so much better&quot;:


比美国好(better than America)
比美国好得多(much better than America)
比美国好得多了 (so much better than America)

*It uses the final particle &quot;了&quot; to increase the emphasis.  The 'so' in &quot;so much better&quot; functions the same way.