mardo

Tuesday, and the sixth of the seven weekday names to get a page here. The course now has lundo Monday, mardo Tuesday, merkredo Wednesday from the sibling band of this same chapter, vendredo Friday, sabato Saturday and dimanĉo Sunday. Only ĵaŭdo, Thursday, is still missing, and it sits at rank 2620, which puts it in the next chapter but one. Six down, one to go.

Lowercase, always. Esperanto does not capitalise the days of the week, the months, or the names of languages and nationalities. It is mardo, januaro, la angla, and a capital letter on any of them is a straight interference error from English or German.

The accusative of time. This is what the word is really here to teach. A noun in the accusative can do adverbial duty and answer "when?" without any preposition at all:

• mardon - on Tuesday
• ĉiun mardon - every Tuesday
• la venontan mardon - next Tuesday

You can also say en mardo or dum mardo, and nobody will misunderstand, but the bare -n is the idiomatic form and the one Zamenhof used. Note that antaŭhieraŭ and its family never take this -n, because they are already adverbs and have no noun ending to convert. Full detail in the time expressions article.

The etymology is a small pleasure. Mardo is Latin Martis dies, the day of Mars, arriving through French mardi, Spanish martes and Italian martedì. English Tuesday is the day of Tiw, the Germanic war god the Romans identified with Mars when they matched the two pantheons up. So the English and the Esperanto name the same god by different names, which is why they look nothing alike and mean exactly the same thing.