Very much; by a very large amount.

Very much; by a very large amount非常地；差距非常大地。

It is a strong word for size of difference, and this is the key to using it: 'vastly' almost always sits next to something that already means change, difference, or comparison. So you get 'vastly improved', 'vastly different', 'vastly increased', 'vastly outnumbered', 'vastly better', 'vastly more expensive', 'vastly overrated'.

It is a strong word for size of difference它是形容差距大小的一個強烈字眼，and this is the key to using it這也是用它的關鍵：'vastly' almost always sits next to something that already means change, difference, or comparisonvastly幾乎都會出現在本身就帶有變化、差異，或比較意味的字旁邊。So you get所以你會看到 'vastly improved', 'vastly different', 'vastly increased', 'vastly outnumbered', 'vastly better', 'vastly more expensive', 'vastly overrated'大幅改善、天差地遠、大幅增加、人數遠遠居於劣勢、好上許多、貴上許多、被大大高估。

English speakers do not usually say 'vastly happy' or 'vastly tired', even though those are also 'very' — with a plain adjective we say 'extremely'.

English speakers do not usually say 'vastly happy' or 'vastly tired'英語母語者通常不會說'vastly happy'或'vastly tired'，even though those are also 'very'即使那也是「很」的意思——with a plain adjective we say 'extremely'搭配普通的形容詞時，我們會說'extremely'。

There is an older, more literary use meaning simply 'extremely' ('I am vastly pleased'), which you meet in old novels and which now sounds either very posh or joking.

There is an older, more literary use meaning simply 'extremely'有一種比較舊、比較文學性的用法，單純就是「非常」的意思（'I am vastly pleased'像'I am vastly pleased'（我非常高興）），which you meet in old novels你會在舊小說裡遇到，and which now sounds either very posh or joking而現在聽起來要嘛很講究、要嘛像在開玩笑。

In normal modern use it is a formal-ish written word: news reports, business writing, essays. In conversation people say 'way better', 'a lot more', 'totally different'.

In normal modern use在一般現代用法裡 it is a formal-ish written word它是偏正式的書面字：news reports, business writing, essays新聞報導、商業文章、論說文。In conversation在日常對話裡 people say 'way better', 'a lot more', 'totally different'大家會說「好太多」、「多很多」、「完全不一樣」。

Its power comes from the picture inside it — 'vast' means huge like an ocean or a desert — so save it for gaps that really are enormous, or it loses its force.

Its power comes from the picture inside it它的力道來自字裡藏的畫面——'vast' means huge like an ocean or a desertvast的意思是像海洋或沙漠那樣的遼闊——so save it for gaps that really are enormous所以要留給真正巨大的差距用，or it loses its force不然它就會失去力道。