哎

a̅i = Ø + ai1

hey! / (interjection used to attract attention or to express surprise or disapprobation)

哎 = 口 + 艾 : Albert Einstein (Ø) wants to warn the public about the dangers of aids (艾). In front of the airplane (ai1) he dresses as a mandarin (口) and shouts "hey!" (哎) at the people to get their attention.

哎 character breakdown

哎
- 口
- 艾
  - 乂
    - 丿
    - ㇏
  - 艹

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).

艾

ài = Ø + ai4

surname Ai

艾

ài = Ø + ai4

Chinese mugwort or wormwood / moxa / to stop or cut short / phonetic "ai" or "i" / abbr. for 艾滋病[ai4 zi1 bing4], AIDS

艾 = 乂 + 艹 : Albert Einstein (Ø) cut himself, so he wanted to treat his wound with wormwood (艾) and mugwort (艾) in the airplane's bathroom (ai4). He finds that he accidentally used artificial lawn (艹) instead, and much worse, it has been used by someone else before. Quickly he uses a pair of pliers (乂) to draw out the artificial lawn again to stop (艾) getting aids (艾).

艾

yì = y + Ø4

to mow / to cut / to reap / to redress