Commas before and

Answer 1

I assume that you are asking whether one should use a comma before 'and' when writing a series of items. For example:

When you are going shopping, please buy milk, eggs, butter, and cheese.

Unfortunately, there is no one concrete answer to this question. In fact, the question as to whether one should put a comma before the 'and' when completing a series is so hotly debated among grammar enthusiasts that it has received a name: the Oxford comma.

Those who support the use of this comma before the 'and' argue that when a comma is not used, it makes the last two items seem as if they are part of one unit. For example:

My favourite types of sandwich are egg salad, tomato, peanut butter and jam. Though technically it is not grammatically correct if one takes 'peanut butter and jam' to be a single type of preferred sandwich, it is a common misreading of the sentence.

However, for those who do not support the use of this comma, the argument is that 'and' takes the place of the comma--that and literally has the same meaning as a comma in this context. An example would be this:

I need to buy pencils, erasers, pencil crayons and looseleaf.

There is no real 'right' answer to this question; it is merely a matter of consistency and personal preference. I like to use a comma before 'and', but if you don't, that is also fine. The important thing is that you remain consistent. If you are going to put a comma before 'and' in a list, then always do it.

Answer 2

when listing things like a shopping list, you never have a comma before the and. Example: apples, bananas, grapes and watermelon