[Grammar] Why don't we use the plural form?

[Heidi]

Dear teachers,

May I please ask you why in the sentences below we don't use the plural forms of the words 'name' and 'length'? We have many months and each month has a different name, so we do have many names, don't we?

"Why do months sometimes change their name and length? August used to have 30 days, and, because..."

 

[Raymott]

Dear teachers,

May I please ask you why in the sentences below we don't use the plural forms of the words 'name' and 'length'? We have many months and each month has a different name, so we do have many names, don't we?

"Why do months sometimes change their name and length? August used to have 30 days, and, because..."

If you changed it to, "Why do months sometimes change their names and lengths?, you could just as easily ask, "Why do they refer to the months' names, when each month only has one name?"Sometimes you just have to choose the lesser of two evils.