Finnish, German, English, Ukrainian, Estonian, Swedish, Latvian, Dutch, Lithuanian, Russian, Polish, Spanish, French. A little Italian and Portuguese as well. I did manage to explain some simple things in Czech some days ago, and I can read south-Slavic languages surprisingly well. And often decipher the main point of a text in Romanian.

Almost no Hungarian or Mandarin, though very simple questions are possible anyway. And then of course I can read Norwegian and Danish reasonably well, because if you know Swedish, English, German and Dutch, you already know Danish. And for a similar reason, Slovak goes.

I can speak less than five words of Albanian, Basque, Greek, Welsh, Breton, any Gaelic language or any Sámi language. Those are something should probably learn a bit, at least.

Diction needed.

One of the languages I am not sufficiently fluent in, yet, is that of Australia and USA. What does “Diction needed” mean in this context?

Diction is speech (like dire in French), and it was a bit of wordplay on the common expression ‘citation needed’ like the other commenter said :) Basically joking that a claim to speak a language should be backed up by saying something in that language to be believed.