: :

Combinations of underlining and colons are used to indicate intonation contours, as follows: If the letter(s) preceding a colon is underlined, then there is an "inflected" falling intonation contour (you can hear the pitch turn downward on the vowel). If a colon is itself underlined, then there is an inflected rising intonation contour (i.e., you can hear the pitch turn upward on the vowel). So, in TG, the "Oh:::.", arrow 1, has an upward inflection while it is being stretched (even though it ends with falling intonation, as indicated by the period). On the other hand, "ta:ll", arrow 2, is inflected downward ("bends downward," so to speak, on the vowel), over and above its "period intonation."