Allora (so, then, well) is one of those filler words that’s highly useful when thinking of what to say in Italian. It buys you a little time and tells the listener you’re thinking things over, especially when used by itself, or to introduce a sentence. Used by itself, it can express impatience:
Allora! (Come on!, Hey!)
or can be introductory:
Allora, vediamo. (Well then, let’s see.)
But what does it really mean? The word actually comes from the Latin ad illa horam (at that time). And, not surprisingly, allora can indeed mean “at that time,” when it refers to the past. It’s true that we can use “then” as a translation, but “then” has other meanings as well, so it helps to have an idea of allora’s underlying meaning.
The following example gives you the idea:
Io penso che tu lo sappia che prima di allora...
I think that you know that before that time...
eh, Roma aveva un grandissimo problema proprio per le alluvioni.
uh, Rome had indeed a huge problem with flooding.
Captions 36-37, Anna e Marika - Il fiume TeverePlay Caption
In a video series about the recent history Italian cuisine, Chef Gualtiero Marchesi is telling the story of his restaurant. He uses allora twice in the same sentence, but to mean different things: the first instance is the filler that gets used so often; the second instance is a bit more specific.
E allora proponevo questo piatto, il grande antipasto di pesce,
And so I offered this dish, a large fish antipasto,
che allora aveva tre versioni.
which at that time had three versions.
Captions 12-13, L'arte della cucina - L'Epoca delle Piccole RivoluzioniPlay Caption
Allora can also mean “in that case.” In fact, the second instance of allora in the above example could also possibly have meant “in that case.” In the following example, the meaning is less ambiguous. You might be asking, can’t we just say “then”? In this case, yes, because it’s clearly an “if/then” situation, but “in that case” helps us understand allora more fully.
Quindi, la differenza è minima, però capirete quando vedete:
So, the difference is minimal, but you'll understand when you see:
è un aggettivo o un avverbio?
is it an adjective or an adverb?
Se io parlo di un avverbio, allora è sempre "bene",
If I'm talking about an adverb, in that case it's always "bene,"
una situazione, se parlo di un aggettivo uso "bello" o "buono".
a situation, if I'm talking about an adjective I use "bello" or "buono."
Captions 24-27, Corso di italiano con Daniela - Le parole: bello, buono e benePlay Caption
In place of allora, Daniela could have used in tal caso or in quel caso to mean “in that case,” but since she is speaking informally, she has used allora.
We use allora a lot in speech without even thinking about it, so being aware of where it comes from may give us una marcia in più (“an edge,” literally “one more gear”).
In a nutshell:
Allora is a filler word much of the time (well, so, then).
Allora comes from the Latin ad illa horam (at that time) and means precisely that, when talking about the past. Allora means “then” in several senses of the word (well/so, at that time, in that case).
Just for fun:
Allora, vi racconto un po’ della mia storia. Da bambina portavo una gonna per andare a scuola. Allora era vietato alle ragazze mettersi pantaloni. Il sabato, per giocare, allora potevano mettere anche i pantaloni. Allora! Mi ascoltate? No? Allora, non vi dico più niente.
Well, I’ll tell you a bit about my past. As a girl I wore a skirt to go to school. At that time girls were not allowed to wear pants. But on Saturdays, to play, then (in that case) they could wear pants, too. Hey! Are you listening to me? You’re not? In that case, I won’t tell you anything more.
There are a great many instances of allora in Yabla videos. By doing a search and just scrolling through, now that you’re in the know, you’ll be able to figure out if someone’s thinking of what to say, or if he or she is being more specific.