sand(沙子)—sands(沙滩)。
– The children played with sand on the beach.(孩子们在沙滩上玩沙子。)
– The sands of the desert are endless.(沙漠的沙滩无边无际。)

spirit(精神)—spirits(情绪;烈酒)。
– We should have a spirit of cooperation.(我们应该有合作精神。)
– He is in high spirits today.(他今天情绪很高。) / He drank a glass of spirits.(他喝了一杯烈酒。)

time(时间)—times(次数;时代)。
– What time is it?(现在几点了?)
– I have been there several times.(我去过那里好几次了。) / We live in modern times.(我们生活在现代。)

water(水)—waters(水域)。
– Please give me a glass of water.(请给我一杯水。)
– The ship sailed in the rough waters.(船在汹涌的水域中航行。)

wood(木头)—woods(森林)。
– The table is made of wood.(这张桌子是木头做的。)
– He went for a walk in the woods.(他去森林里散步。)