I find the commas between coordinate adjectives unnecessary.
For example, the followings seem to be both fine to me.
It’s a bulky, heavy box.
It’s a bulky heavy box.
Is that so?
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Sign up to join this communityI agree, both versions seem fine. I parse them slightly differently, though.
It’s a bulky, heavy box.
This means the box is bulky, and the box is heavy.
It’s a bulky heavy box.
This means the heavy box is bulky.
Now, in most cases, this will actually mean exactly the same thing. There are situations where there is an actual difference, though.
When you are talking about several heavy boxes, some of which are bulky, some of which are not, you would probably use the second version, whereas when you are talking about boxes with different properties, you would use the first:
Lifting heavy boxes is not really difficult, as long as you know that a given box is heavy. When you see a bulky heavy box, you can probably guess it's heavy. The problem is with small heavy boxes. If you try to pick up a shoe box containing lead, it is a lot heavier than you would expect it to be.
versus:
We managed to move all the boxes to the third floor, except for that one. That is a really bulky, heavy box; we couldn't get it up the stairs.
[1] It’s a bulky, heavy box.
[2] It’s a bulky heavy box.
There is a difference. The punctuation here distinguishes coordination from the stacking of modifers.
In [1] "box" is modified by a coordination of adjectives giving the meaning "box that is both bulky and heavy".
In [2], by contrast, there are two layers of modification: "box" is modified by "heavy" to form the nominal "heavy box", and this is in turn modified by "bulky", giving the interpretation "box that is bulky by the standards applicable to heavy boxes".
Thus the syntax is different and there are two different shades of meaning, but for most practical purposes in this case it doesn't make a great deal of difference.
One aspect of commas which is less often touched on in grammatical rules is that they also set the phrasing with which the text is to be read.
How would you say that? For myself, I'd probably have a small pause between "bulky" and "heavy", so I'd insert a comma. On the other hand, I'd probably say "a huge steaming pile of manure" without any pauses, so I would tend not to insert a comma between "huge" and "steaming".
Grammatical rules primarily exist to guarantee successful communication - but (to paraphrase Jesus) the rules are made for the good of the communication, not the communication for the good of the rules. If you know why you're not following a rule, then you know enough to recognise whether the resulting text is better or worse at communicating the concept to your audience. The reason for the rules existing in the first place is that many people aren't competent enough with language to recognise this.
As per the rule of punctuation, comma is needed between SIMILAR types of adjectives before the noun. These are known as 'Coordinate adjectives : It's a bulky, heavy box. [ opinion _ opinion ] Here, 'bulky' is modifying 'box'. 'Heavy' is modifying 'box''. Similarly, The long, narrow path. Some elegant, delicious food.
But no commas are needed between DIFFERENT types of adjectives before the noun. These are known as 'Cumulative adjectives' : A big square blue box. [ size _ shape _ colour ] Here, 'blue' is modifying 'box'. 'Square' is modifying 'blue box'. 'Big' is modifying 'square blue box'.
Hope, it is now quite clear. If you write " It's a bulky heavy box", your sentence is incorrect in respect of the rules of punctuation.