Interested in Language
I think the answer is 'are contending' because 'groups' is countable noun but i'm unsure.
A number of groups is/are contending for power in the new government.
Thank you for teaching me!
***** NOT A TEACHER *****
I have good news.
The rule is very easy.
A number of X = plural verb.
The number of X = singular verb
A number of groups are participating in the Olympics.
The number of groups participating in the Olympics is 75.
A number of students are going to Paris.
The number of students going to Paris is 25.