I agree

No, because given that "ankaux" generally comes before the word it modifies, putting it in front of "horlogxoj" would change it to "watches are also clocks." That is, watches are multiple things - say, jewelry and clocks.

The original sentence is about multiple kinds of clocks - say, wall clocks are clocks, and watches too are clocks.

It comes before the word it modifies.

• Ankaux mi iros al la festo. (You are going and so am I.)
• Mi ankaux iros. (I'm promoting your event and also coming to it.)
• Mi iros ankaux al la festo. (I am going a few places including the party.)

Note that you can't use "ankaux" do join two thoughts together.

• I like to ski. Also, skiing is good exercise.
• Mi sxatas skii. Cetere, skiado estas bona ekzerco.

If that was the only reason Duolingo complained, you should have reported it. Of course provided you spelt it without space.

Fun Fact: The English word "clock" is related to the German word for bell. Timepieces with bells in them were called clocks. Smaller timepieces without bells required that you watch them to know the time - and so became known as watches.

The Esperanto word horloĝo doesn't suffer from this etymological baggage.

I've just reported "Watches are timepieces, too", hopefully it will be added as an option.

I thought so too, but if you google the definition, it says under synonyms (for watch) "small clock"

Depends on the language. In Malay — and I'm willing to bet in many other languages as well — clock is "jam" and watch is "jam tangan", literally "hand clock".

best/o

1. Ĉiu animalo escepte de homo
2. Homo stulta aŭ kruda kiel besto

.

So - in a figurative sense, you're correct, but literally, by definition, you're mistaken.