Today's Parola del Giorno is the expression: Una rondine non fa primavera. This expression means One swallow does not make a summer (or one swallow does not a summer make).
It literally means one swallow does not make Spring. It means that a single instance of something does not necessarily indicate a trend. In other words, just because one good thing has happened, it doesn't mean that other good things will necessarily follow.
See the expression used below:
Anche se hai fatto bene l'ultimo test, sappi che una rondine non fa primavera. Per superare questo corso devi ancora studiare tanto!
Even if you did well on the last test, know that one swallow does not make a summer. In order to pass this course, you still have to study a lot!