# Plural or singular when being asked “what's the unit of a number”

Example 1: "What's the common measuring unit of the speed of a car in the United States?" Do we say "It's mile per hour" or "It's miles per hour"?

Example 2: "Please enter the degrees of the angle:" as the text for an input field. Is it okay to say "Please enter the degree of the angle" too?

Example 3: "Angle (degrees)". Also a text for an input field. Should we write "Angle (degree)" instead?

This is NOT a question asking whether units are singular or plural following a number. That has been already well answered here.

One of the answers in the link mentioned that "All of the units are inherently plural". If this is true, we should say the unit for speed in the metric system is "meters per hour" instead of "meter per hour". Since this is a single answer and it doesn't have any reference, I'm not sure if it's correct. Even if it's true, why "m/s" then?

• "m/s" is not for sentences. It's for equations and equation fragments. "Miles per hour" is for sentences and sentence fragments. In general, use the plural for your sentences, e.g. "Give your answer in inches." But your second example looks a little funny to me. Typically I'd see "Angle A measures _____ degrees." – aparente001 Oct 10 '19 at 5:59

## 1 Answer

1. It's mile per hour

If you don't want to deal with s in the input field, you can write

• "Please enter the degree(s) of the angle:"
• "Angle (degree(s))"
• It's only "mile per hour" if the speed is one mile per hour or we are talking about the unit in the abstract as in "What's the mile per hour limit?", that's similsr to asking "What dollar per hour rate do you charge". If we say "What's the speed limit around here?" Someone might say "Thirty miles per hour" and we could also ask "How many miles per hour can we do on the freeway?" Both mile per hour and miles per hour can be correct in different circumstances. – BoldBen Oct 10 '19 at 4:26