I wrote: Qual'effetto hanno. It is wrong. Can you ever replace the e at the end of quale with the " ' "? I thought, since there was an e at the end of the first word and and e at the beginning of the second that you could replace the first e with " ' ".
Quale has a truncated form "qual" so it's never elided (i.e. no apostrophe); however it's only used in a few selected cases, e.g. qual รจ, qual era, la qual cosa...