Radical ε£
10 strokes
mouth ε£ (5) + ah ιΏ (143a) = eh! ε
This character is used as an exclamation, added to a sentence to express surprise, admiration, regret, etc. depending on the context. When at the end of a sentence, it has a neutral tone; if the preceding word ends in -n or -ng it changes into εͺ (Character 99) and is pronounced na.

The doctor says, βOpen your mouth and say βahβ β yes, these tonsils will have to come out.β βthat bad, eh?β the patient says in surprise. / The giant says βAhβ in sympathy (he had to have his tonsils out as a child and heβd cried!)