I was always interested in using Singular or Plural after some words as 'a family; ‘a police’, ‘a group of people’, ‘a lot of friends’, ‘lots of books’, ‘the majority of the voters’ etc.
Did you think about this?
If yes, you can receive the answer, listening to my interview with Richard, a native English speaker from England.
Here is the link to our conversation ‘SINGULAR OR PLURAL AFTER SOME WORDS’:
I think these expressions are similar to ‘a number of’ - that’s why both are possible - Sg and Pl. For example, for ‘means’ I found such examples:
For example in Sg;
A means was found to do it.
Every means has been tried.
It is a safe means.
The quickest means of travel is by plane
And in Pl: Her means are limited.
All such means are unpleasant.
Are the means ever justified by the end.
All means have been tried.
The additional difficulty is that boith words are at the same time Sg and Pl because of the -s at the end.
“Series” and “species” are both words whose singular and plural forms are identical. “A series” is a row, set or line of things, and if you happen to have two lots of rows, sets or lines, then you have “two series”. Likewise, “a species” is a single grouping or class identified as belonging together because of some common feature or features … and in the plural, we would say (for example) that the animal world contains “many different species.”