Singular or plural.
These words are plural, so they take a plural verb:
• My trousers are too long, (not 'is too long')
You can also use a pair of + these words:
• Those are nice jeans, or That's a nice pair of jeans, (not 'a nice jeans')
• I need some new glasses, or I need a new pair of glasses.
B/ Some nouns end in -ics but are not usually plural. For example:
athletics/ gymnastics/ mathematics (or maths)/ physics/ electronics/ economics/ politics
• Gymnastics is my favourite sport.
News is not plural.
• What time is the news on television? (not 'are the news')
Some words ending in -s can be singular or plural. For example:
means ==> a means of transport ==> many means of transport
series ==> a television series ==> two television series
species ==> a species of bird ==> 200 species of bird
C/ Some singular nouns are often used with a plural verb. For example:
government/ staff/ team/ family/ audience/ committee/ company/ firm
These nouns are all groups of people. We often think of them as a number of people (= 'they'), not as one thing (= 'it'). So we often use a plural verb:
• The government (= they) want to increase taxes.
• The staff at the school (= they) are not happy with their new working conditions.
In the same way, we often use a plural verb after the name of a sports team or a company:
• Scotland are playing France next week (in a football match).
• Shell have increased the price of petrol.
A singular verb (The government wants... / Shell has... etc.) is also possible.
We always use a plural verb with police:
• The police have arrested a friend of mine, (not 'The police has')
• Do you think the police are well-paid?
Note that a person in the police is 'a policeman / a policewoman / a police officer' (not 'a police').
D/ We do not often use the plural of person ('persons'). We normally use people (a plural word):
• He's a nice person, but They are nice people.
• Many people don't have enough to eat. (not 'doesn't have')
E/ We think of a sum of money, a period of time, a distance etc. as one thing. So we use a singular verb:
• Twenty thousand pounds (= it) was stolen in the robbery, (not 'were stolen')
• Three years (=it) is a long time to be without a job. (not 'Three years are...)
• Six miles is a long way to walk every day