Partitive nouns, as the word suggests, are nouns which express the concept that the item described is only a part but not the whole of the item then referred to. For example (with the partitive nouns underlined) :
a slice of bread a blade of grass a drop of rain
a piece of research a clove of garlic a bit of cheese
a teaspoonful of sugar an item of news a bout of 'flu
a fit of anger a cup of tea a bottle of wine
a bar of chocolate a third of the water a pint of milk
As these examples show, they are typically used with nouns used uncountably (bread, news, rain, anger) etc, but being themselves countable can be used to allow you to "count" those nouns :
two slices of bread regular fits of anger several items of news etc
Some partitives - such as a piece of or a bit of - can be used with a wide variety of nouns. Others are more restricted in their collocations - for example, a clove of . Try looking at the examples above. How many words can you think of which collocate with each partitive? Do they come from different lexical fields or the same lexical field(s)?
Confused? If as you've been reading this you've found yourself thinking But... but..., don't worry - you're not alone. There's a lot of confusion about the term, with different grammars discussing it in different ways. I therefore recommend also looking at the following :
- An answer to a forum post that I wrote a while back, which still seems to me to be logical: Partitives and Quantifiers : What's the Difference?
- This article by Richard Nordquist : What are Partitives in Grammar?
- This article on ELT Concourse : Classifiers, counters, partitives, collective nouns and assemblages