哟

yo̅ = y + o1

Oh! (interjection indicating slight surprise)

哟 = 口 + 约 : Maud Younger (y) is going to go on a date (约). To freshen up her breath she eats a mandarin (口) in front of the observatory (o1), but she accidentally swallows the mandarin whole and exclaims "哎哟" out of pain and surprise (哟).

哟

喲

yo = y + o5

(sentence-final particle expressing exhortation) / (syllable filler in a song)

哟 character breakdown

哟
- 口
- 约
  - 勺
    - 丶
    - 勹
      - 丿
      - ㇆
        
        一
        
        亅
  - 纟

口

kǒu = k + ou3

mouth / classifier for things with mouths (people, domestic animals, cannons, wells etc) / classifier for bites or mouthfuls

Mnemonic symbol: 口 shall be represented by a mandarin. Karl Marx (k-) is enjoying a mandarin in the outhouse's living room (ou3).

约

約

ya̅o = y + ao1

to weigh in a balance or on a scale

约

約

yue̅ = yu + e1

to make an appointment / to invite / approximately / pact / treaty / to economize / to restrict / to reduce (a fraction) / concise

约 = 勺 + 纟 : Marilyn Monroe is on a date with a silk worm in front of the elevator. Marilyn wants to show the silk worm around, and so she carries him around on a little silver spoon.