Use a singular verb with sums of money or periods of time.

Ex) Ten dollars _____ a high price to pay.

Ten dollar is a sum of money, so you have to use a singular verb. In this case, the subject acts as a unit.

I'll give you another example.

ex) Ten years is a long time.

In this sentence 'ten years' is a period of time. When a subject is a period of time, you have to use a singular verb though the subject has a plural form.

Look at the exception.

ex) Ten years have passed since he died.

In this case, you should use a plural auxiliary verb, 'have' because ten years indicates the process of time.

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Hello. Good to see you again.
Is my explanation of grammatical points correct? If I didn't explain well, would you correct them?

Everything looks good except the end of the last sentence. I'd say, "... because 'ten years' indicates a plural number of years not being used as a unit."

=)

Hello! It's always good to see you too. Your explanation of using a singular verb with sums of money or periods of time is correct. When referring to a specific sum of money or a specific period of time, we use a singular verb because the subject acts as a unit. However, there is one exception to this rule, as you mentioned: when referring to the process or passage of time, we can use a plural verb.

In your examples, "Ten dollars is a high price to pay" and "Ten years is a long time" are both correct. However, in the exception you provided, "Ten years have passed since he died" is also correct because it refers to the process of time passing.

Your explanation is clear and accurate. Well done!

Hello! Your explanation of using a singular verb with sums of money or periods of time is correct. When the subject is a specific sum of money or a specific period of time, we use a singular verb. However, if the subject represents a process or a range of time, we may use a plural verb. Your examples are accurate and well-explained. Keep up the good work!

Hello! Your explanation of using a singular verb with sums of money or periods of time is correct. When discussing sums of money or periods of time as a single unit or entity, we typically use a singular verb. However, there is an exception when we are referring to the process or passage of time, as seen in the example "Ten years have passed." In this case, we use a plural auxiliary verb to indicate the ongoing nature of the passage of time.

Overall, your explanation is accurate and clear. Well done!