Don’t split sentences
In panels/sound/cc-speaker-test-button.c
/* Translators: This is the tooltip for a speaker test button, %s is an already translated
speaker position, like "Front Left" or "Rear Center". */
tooltip_text = g_strdup_printf (_("%s Speaker"), pa_channel_position_to_pretty_string (position));
That may make it impossible to properly translate in some languages. Never split sentences.