1. Past tense forms in English
stopped, walked, coughed, kissed, leashed, reached
stabbed, wagged, achieved, buzzed, soothed, bridged
steamed, stunned, pulled
played, flowed, studied
wanted, located, decided, guided

2. The regular past tense form in English is pronounced as [t] when the word ends with a voiceless consonant, [d] when it ends with a voiced sound, and [ɪd] when it ends with [t] or [d].

3. Plural rule z   / [-voice, +cons]______ (Devoicing)
z  z 剩余位置

4. Obligatory Contour Principle (OCP)
No identical adjacent autosegments. (Goldsmith 1976)

5. 3. Non-linear Phonology
These theories began as a method for representing prosodic features such the stress in complex words, so that their different levels of stress are represented not by linear orders but by a metrical grid:

6. Later the method was extended to the representation of earlier linear rules.

7. Feature Geometry

8. Plural rule (1) [+cons] [+cons] [-son] root [-son] plural z
Laryngeal Laryngeal
[-voice] [+voice]

9. Plural rule (2) Ø  X /X____________X [-cons] [+cons] [+cons]
[+strid] [+strid]
[COR] [COR]

10. Past tense rule (1) [+cons] [+cons] [-son] root [-son] past d
Laryngeal Laryngeal
[-voice] [+voice]

11. Past tense rule (2) Ø  X /X__________X [-cons] [+cons] [+cons]
[-cont] [-cont]
[-nas] [-nas]

12. 4. OT
The ranking of the constraints is represented by a “tableau”.

13. Review of some constraints
*VOICEVOICE: consecutive obstruents must be identical in voicing within a syllable.
DEP-IO: insertion of segment is prohibited.
IDENT-IO: input segment and the corresponding output must be identical.
OCP: No identical adjacent autosegments.

14. OT tableau for plural forms (1)

15. OT tableau for plural forms (2)

16. OT tableau for past forms (1)

17. OT tableau for past forms (2)

18. Ranking of the constraints
OCP » DEP-IO » *voice-voice » IDENT(F)