Japanese notes
Thank you
γ©γγ Do-u-mo: can be used by itself as casual informal thanks.
γγγγ¨γ Arigatou: most casual form, among close friends or to socially lower standing.
γ©γγγγγγ¨γγγγγΎγ Doumo arigatou gozaimasu: casual emphatic form, present tense
γγγγ¨γγγγγΎγ Arigatou gozaimasu: Standard polite everyday form, present tense
γγγγ¨γγγγγΎγγ Arigatou gozaimashita: Standard polite everyday form, past tense, thanks for a thing already done; the final i in gozaimashita tends to be unvoiced and may sound more like gozaimashΒ·ta.
Analysis
γ©γγ Do-u-mo: expresses gratitude or sometimes doubt. This generally softens the meaning and adds emotion. Thus, while γ©γγ (doumo) amplifies gratitude, it can imply a sense of βIβm very grateful, and Iβm also humbly aware that I might be imposing a βburdenβ on you to receive my gratitude, but since we have a closer relationship I am emboldened to express my gratitude openly.β In other words, this softening effect can be interpreted as a slight sense of humility or even a hint of apology for the βburdenβ of receiving gratitude.
γγγγ¨ A-ri-ga-to: derives from the adjective/attribute γγγγγ (arigatai, βgratefulβ or βthankfulβ), which combines ζγ (ari, βto exist/beβ) and ι£γ (katai, βdifficultβ or βrareβ) to originally mean most rare and precious, almost miraculous and astonishing that it should exist.
γγγγγΎγ Go-zo-i-ma-su: (the βΓΌβ of the ending βsuβ is muted or even silent)
Note
longer vowels tend to sound more polite in Japanese. i and u tend to be unvoiced in busy Tokyo.