One more thing. As a rule of thumb, if you want to mark your sentence as something recent, something new you can say "I have learned a new sentence today". That is, to refer to events in the past twelve hours or less.
I am not saying that you don´t use the "learned" thing, I am saying that if you want to focus on the event not being long past/the "recentness" of it, then you have this option.
So, now you have more than one way to express that.