Ah and Hello

Ah interjection - How surprising, doubtful, or unbelievable.

Hello and ah are semantically related in emphatic exclamation topic. In some cases you can use "Hello" instead the word "Ah" as a noun or a interjection.

Hello noun - An expression of goodwill upon meeting.

Ah and hello are semantically related in boo topic. You can use "Ah" instead the word "Hello" as a noun or a interjection, if it concerns topics such as wow.