sake
1.for the sake of在一般词典里注作“因为”,其实有“由于、为了、为了…的利益”等的意思,并不跟because of,on account of,owing to等完全相同。如可以说He goes to the seaside for the sake of his health,不可说He goes to the seaside for the sake of his illness,for the sake of his illness的意思是“因为生病”。可以说Mary taught for the sake of money,不可说Mary taught for the sake of poverty,for the sake of poverty的意思是“因为穷”。
2.for God's sake,for Jones's sake,for mercy's sake等表达方式里有's。假使那名词并不是专有名词,而且加上了's要多一个音节,习惯上便不加s或不加's,如for goodness' sake和for goodness sake,for conscience' sake和for conscience sake。有时即使并不会多一个音节也不加's,如for safety sake和for fashion sake。
3.for our sake含有“我们各人的目的不同”的意思,for our sakes含有“我们各人的目的相同”的意思。