This is the most inaccurate definition that I have seen on Duolingo which I love and appreciate.
"Metro" by itself is a unit of length, una metro or just metro is one meter of length.
As a measuring instrument, a tape measure or ruler etc. "metro" should have an un in front of it. Un metro means the tape measure or the ruler.
By placing an "el" in front of it, el metro generally applies to a means of transportation. In UK it would apply to the tube, in New York the subway. It can even be used to mean a surface transportation system such as the bus system in Laredo. In Houston the bus system is called The Metro.
There, I have now told you more than I know. Take care
El metro can mean the Metro/subway, the ruler, the length of a meter, or the meter of poetry. A meter of the equipment type like a gas meter or water meter is called el contador or el medidor. A parking meter is a parquimetro. All English terms and spelling are American English (and hopefully not typos)
That's interesting. I have been in London, but never in Scotland nor much in the Northeast. Just out of curiosity, does the London system predate the others? Since subway and metro seem to be used fairly universally in English speaking countries and metro in Romance languages like French and Spanish, I always assumed that the tube either was one of the earlier such systems or involved somewhat different technologies. I do remember some London stations being much farther underground than those I found in the other cities I have been to.
Londres fue primero con el “Metropolitan” pero luego tuvo otro sistema, el “Underground”, y los dos se fusionaron.
1863 Metropolitan Underground Railway, London - the "Met"
1896 Glasgow Subway - "Subway",
1902 Undeground Electric Railways Company, London - “Tube” railways,
1933 London systems merged,
1970 (failed) "Picc-Vicc" tunnel, Manchester,
1980, 1991 (extended), 2002 (most widespread) - Tyne and Wear.
Glasgow es el único que está bajo tierra. Durante un tiempo fue llamado "Underground", más tarde apodado "Clockwork Orange" y luego oficialmente llamado "Subway" nuevamente.
If you had put The meter, you probably would have gotten it correct. El is the not a. But if you do that and get it wrong, report it through the flag icon. I think so many people tend to think the subway because it is called the metro in cities all over the world, that it is possible that the Duo staff didn't think about it. But the difference between the and a will always trigger an error. I do it all the time in Portuguese because the feminine definite article is just a instead of la in Portuguese. And while I know that is true, it is very easy for an English speaker to trip up and say a instead of the.