- ThoT Database

Criteria:

The Persistence Criterion
If a tone is contrastive and it persists in all contexts (i.e., it is not affected by tonal processes which could be regarded as criteria of tonemic status), such tone is considered to be a toneme.
The Extensibility Criterion
If a tonal contour can be realized on a segmental unit (most often, word) represented by a sequence of TBUs, but can also be hosted by a segmental unit of the same level (e.g., a word) consisting of a single TBU, this tonal contour is a toneme.
The Non-Compositionality Criterion
If a language has a tonal contour realized on one TBU composed of levels which are not available in this language as tonemes, this contour is a toneme.
The Single TBU Criterion
If a tonal contour can appear on one TBU as an element of an exponent of a single morpheme, and the contour is not a result of a tonal process (such as tonal spread, etc.), this contour is a toneme.
The Floating Criterion
If a tone can float, it is a toneme
Floating M tone is postulated before the L-toned feet of the "constant" type and after the 3SG subject and non-subject pronouns. It cancels the H and L copying rules, and the H spread rule. Floating M tone is the exponent of the Imperative-Optative morpheme, it is suffxed to a verb and is docked on the final syllable of a verbal stem represented by a heavy foot, otherwise it is deleted.
The Tonal Morpheme Criterion
An additive or replacive tonal (non-segmental) morpheme contains at least one toneme.
M toneme is a component of the MH tonal morpheme of the Habutual Aspect. kṹ ‘to catch’ – kū̃ ‘(he) catches’ wè ‘to speak’ – wē ‘(he) speaks’ ɓɗã̀ã̀ ‘to swell’ – ɓɗã̄ã̄ ‘(it) swells. Floating M is the exponent of the Imperative-Optative marker.
The Shared TBU Criterion
If two level tones can be assigned to one TBU, both tones are tonemes (unless this contour is a toneme, see creteria for the contour tonemes above) , and neither is Ø.
The Activity Criterion
If a tone appears as a part of condition in a tonal rule, it is a toneme.
The Positional Constraints Criterion
If there are positional constraints for a tone relative to some segmental unit, this tone is a toneme.