a large amount of作主語的主謂一致

amount用作名詞時，意為“數量”“金額”等，通常用于 a (great, large) amount of 這類結構，其后通常接不可數名詞。如：

There was a fair amount of traffic on the roads. 路上的車輛頗多。

An increasing amount of organic produce is to be found on supermarket shelves. 越來越多的有機產品出現在超市貨架上。

這類結構用作主語，其謂語的數取決于 amount 的數。如：

在這座橋上花了大量資金。

正：A large amount of money was spent on the bridge.

正：Large amounts of money were spent on the bridge.

注：偶爾也可見到其后接復數可數名詞的用法，但不算普通。如：

The shopkeeper had a large amount of oranges in his storeroom. 店主在貨倉里存有大量橙子。——摘自《朗文當代高級英語詞典》

Even small amounts of these substances are known to cause skin problems. 我們知道這種物質即使是一丁點也會損害皮膚。——摘自《劍橋高階英詞典》