如: This book like (a) part of the broken cup.
This is only (a) part of it; where’s the rest?
但是，part of比a part of通常更為多用，而且a part of有“壹小部分”的含義。
再如： Falling over is part of learning how to ski.
Only (a) part of his story is true.
There is but one china and Taiwan is part of chaia.
應該註意的是，在使用(a) part of …時，of之後的名詞若是單數，通常謂語也就視為單數，同樣，of之後的名詞若是復數，通常謂語也視為復數。
如：This piece of glass seems to be (a) part of a lamp.
Part of the passengers were injured in the accident