How to subtitle offline
Disclaimer: Do not change the timing of the subtitles in SubtitleEdit. Amara does not support this for translations and your subtitles will appear broken when you upload them back to Amara.
Here's a quick way to break lines, do character-per-second checks and a spell check globally offline (for PC users):
1. Download and install Subtitle Edit (http://www.nikse.dk/SubtitleEdit)
2. This, you only do once: go to Options/Settings. In the "General" tab, put "42" in "Single line max. length." Note: depending on your version (I'm using a beta), you may also see "Max chars/sec" below: enter a value for your language (21.9 for most Latin-script based languages)
3. Download the subtitles (translation and original)
4. Open the translated subtitles, and pull up the original (File/Open original subtitle (translator mode))
5. Go to Tools/Fix common errors (or use Ctrl-Shift-F). Remove all selections (click "Select all," then "Inverse selection"). Tick "Break long lines." Click "Next," and click "OK" in the next window.
6. Go over the subtitles (in "List view" - i.e. simply the main window) and look for <br />. This tag marks the place where the line was broken. The lines have been broken automatically, but in some lines, you may need to fix/change the breaks (see http://translations.ted.org/wiki/Transcribing_talks#Line_breaks). You can edit the subtitle you highlighted in the List view in the Text box below (there are even buttons, to the right, that will Unbreak or re-Auto break the lines for you). You have the original English subtitles to the right to help you when a line needs to be rephrased just to make good breaking possible.
When you're done, you can also run a spell check. Subtitle Edit is a great tool for editing subtitles, but remember that Amara currently doesn't allow us to upload drafts with changed timing or split/merged lines. You can also edit with the video downloaded from ted.com, but remember that the timing doesn't fit - the subtitles from Amara don't allow for the TED intro. You can move the subtitles by the length of the intro (Synchronization/Adjust all times), and move them backwards later before uploading the draft. To get more out of Subtitle Edit, explore its Help section and the keyboard shortcuts used in the software.