You use filler words
Instead of umming whenever you can't think of a word, without even thinking about it you use stop-gaps like 'quasi', 'halt' or 'so zu sagen' to buy yourself time – in fact you unconsciously use these words all over the place anyway.
Ideally a sentence might go something like this: “Er war quasi, halt, so zu sagen einfach nicht der Richtige.”
This is an important strategy for speaking German fluently as the extra seconds these words add can be the difference between constructing a grammatical sentence and failing miserably.
You've thrown grammar out the window
Put that grammar book on the shelf where it belongs. Photo: DPA
In the early days you struggled to get every word ending right, and you constantly grappled with word order. But lately you've realized Germans themselves are pretty sloppy with these rules, and now you just let the words flow.
So jemand, jemanden, jemandem has become jemand, jemand, jemand. And you know it's not the end of the world to keep regular word order after 'weil' or 'dass'.
You've adopted a few idioms
Instead of using the most literal way of expressing a thought, you've started throwing in turns of phrase.
But whose beer is it really? Photo: DPA
So to mean 'that's your business' you probably say “dass ist aber dein Bier”, or if someone is acting a bit weird you ask a friend “hat der 'ne Macke, oder was?” to mean 'is there something not quite right with him?'
And if someone asks a question you can't answer with a direct yes or no, you say “Jein” and draw out the word to show how painfully complex the answer is (even though you were simply asked if you want another coffee or not.)
When you get angry you reply in German
This one is the true test. When the red mist comes down it can swallow foreign language skills - meaning all that comes out is a torrent of English abuse. So when you've started ranting in German, you know you're basically native.
Get inspired by Germany's 2013 Volleyball World Cup team! Photo: DPA
Last time you forgot your key did you whisper to yourself 'Mist'? Or when someone moaned at you for taking your bike onto the S-Bahn did you shout back 'halt die Fresse!'? If so, congratulations! That's a surer sign you've mastered German than any Goethe Institute certificate.
You've throw in abbreviations
As we all know, German is full of overly long words. But Germans have to get things done with their days too, so they've found ways round them. And if you're fluent, you probably do the same.
If you're a real German pro, it's the "WM", not the "Weltmeisterschaft". Photo: DPA
When talking in the past, you've replaced ich habe with ich hab; you don't sound out a whole indefinite article, but just say 'n Mann or 'ne Tasse, and you've joined gibt and es into gibt's. A Bibliothek (library) has become a Bibo and a Volksküche is now a Vokü.
If you're really confident, you might have even started making up your own abkürzungen - like Kuhli for Kuhlschrank (fridge) or Schnüri for Schnürbänder (shoe laces).
You've started speaking in dialect
If you've been living in Bavaria for long enough you've probably started calling Brötchen Semmeln and saying 'schau ma mal' for "we'll see." Who knows, you might have even started calling Munich Minga.
They don't even say "hi" and "bye" the same way in Bavaria. Photo: DPA
In Berlin you now say jut for gut. In Hamburg you say schnacken (chat), and in Stuttgart you're speaking something so far from German none of us have a clue what you're talking about!
Baden-Württemberg's honest-to-goodness, 100% real state motto is "We can do anything except Hochdeutsch [standard German]."
You talk the lingo
If your German is tip top, you've realized that there are loads of words in real life that no language book will ever teach you.
You've started saying “Lass es krachen!” or “wir ballern richtich rein!” to mean "we're gonna party!" And words like schlafen (sleep) are so beginner. You'd rather go pennen.
Then there's that weird 'eeh' sound that you keep putting on the end of a sentence for no reason: “was für 'n Penner eeh? Ich meine wirklich, er geht mir voll auf den Sack eeh!”
Dreaming in German
Anyone can speak German while they're awake. But what about putting words into the mouths of other characters while not even consciously thinking about it? Yep, if the mysterious dwarf haunting your dreams is talking backward riddles in German, your skills must be pretty tasty in the lucid light of day.
People get angry when you don't understand
Do people look at you like you're stupid when you don't understand what they say the first time? Don't worry, this is actually a compliment - it means they haven't yet noticed you're foreign and so they can't understand why you're staring blankly at them. You're accent at least must be pretty smooth.
You've started using English again
Imagine an artist who could paint the next Mona Lisa if he wants to, but makes his money drawing stick men instead. Of course you could only use the German words, but you'd be so much more hip if you start throwing in English words in the middle of a sentence instead.
Watching movies without subtitles
When you first started learning German you probably watched movies with subtitles in English. Then you switched to German subtitles. Now though you're confident enough to decipher Till Schweiger's grunt without any help at all.
If you can get through all five hours of "Das Boot" in German, you're a true hero. Photo: DPA
Can you do it for Bavarian films like 'Wer früher stirbt ist länger tot'? Then you're beating many north Germans who are lost without subtitles for south German cinema.
Getting the news in German
But then, if you're truly fluent you probably won't even be reading this article. You prefer to leaf through the pages of Süddeutsche Zeitung or Die Welt instead - not because their articles are more stimulating than those found on The Local, but because you have to think less about the meaning of what you're reading.