This is the 6176th most frequent Spanish word.
anno
"Anno" is not a correct Spanish word. It might be a misspelling of "año," which means "year" in English.
In this sentence, 'año' is used to quantify a unit of time within which actions or events can occur.
En un año aprendes muchas cosas.
In a year, you learn many things.
In this sentence, 'año' is used to denote 'year', referring to the period of time comprising 365 or 366 days.
El año pasado fue muy interesante.
The last year was very interesting.
Here, 'años' is the plural of 'año', indicating multiple years in the past.