I know native Japanese words are typically written in either kanji or hiragana; but if one were to write them in katakana for any reason, how would they represent the “diphthongs” (I don’t know what to call them) おう and えい in words like ありがとう and 先生? Would you use the vowel lengthener ー as in センセー or write the vowels out separately as in センセイ?
1 comment
I would use センセイ for more neat and proper tone and センセー for more casual tone. I’m a native but this comes strictly from feeling but with no knowledge in formal rules regarding this (if there ever were one), so I’m not sure if you should take this as an answer.