Why did they change the pronunciation of "Klingon"?

The "ngan" portion is an identifier for a particular people/person, similar to the Klingon words for a Romulan person (romuluSngan) and a Terran person (teraSngan) spoken in STV:TFF (1:09 onward):

Yes, I was one of the ones who pointed this out about Kahless. But people who were complaining about it didn't care even when the facts were brought up. It's funny how that works.

Kor

 

Worf tried to say it when he wanted to get married to Kehleyr, but instead of tlhIngan jIH, he said teehingan ji XD

qeylIS

That's cause it's TomalAk

tera'ngan

 

I'm pretty sure they only said "Kling-In" in "Errand of Mercy". In the second and third seasons it's "Kling-On".

I chalk it up to nothing more than working out the pronunciation in their first appearance. It's like when the Bajorans were called the "Bajora" in "Ensign Ro". They're never called that again, afterwards.

 

DeForest Kelly mispronounced a lot of made-up words. In "The Corbomite Maneuver," he pronounced Balok's name to rhyme with "phallic." In "Journey to Babel," he calls Spock's childhood pet a "sellet" -- even though he just heard Amanda pronounce it as "say-laht"!

 

Most likely. I remember several references to “Vulcanians” in S1 TOS as well. Was quite jarring. Same kind of thing, I imagine.

 

I’m pretty sure Eleen from “Friday’s Child” also said ‘Kling-in.’

 

Even when they do say the word with the "ON" sound they double up the "g" a lot of the time, like putting "cling" and "gone" together. Not sure if that was clear in my OP, that's why the TNG era change is more jarring.

 

Then there was that one Admiral in the Enterprise pilot who called them “Klingots”.

 

I chalk that up to her wanting Bob the discount Klingon to get hot under the collar. She's pretty snotty at him when she says it.

 

If anyone deserved to be called a "Kling-In", it's him. "Klingon" is too good for Discount Bob.

 

In "Arena", Shatner says "Meh-trones" instead of "Meh-trons."

 

As far as TOS goes, I think the only time I heard it pronounced as "Kling-in" was by Julie Newmar (who played Ele-en, wife of the High Tyr) in TOS - S2 "Friday's Child"; but in that same episode, everyone else was pronouncing it "Kling-on".

So yeah, like others said, it was probably just actors and crew being presented with a made up name, doing their on interpretation, and the director/script supervisor/other cast in the scene not making a big deal out of it, or letting the actor 'act'.

Hell, in the TAS episode "The Pirates of Orion" William Shatner pronounces 'Orion' of "Orion Pirates" - which he and everyone else in the case pronounced as 'o-RYE-en' in the live action TOS - S2 "Journey to Babel" as 'OR-ee-un' - while Leonard Nimoy and the rest still say is as 'o-RYE-en' (but to be fair for TAS all the lines were recorded separately in a booth on different days, they never had actors working together for the voice overs.)

 

Actually, I think it’s the other way around, it’s consistently -ON in Errand of Mercy, but Season 2 is where they experimented with -IN. I don’t remember where I read this, but, I think they were trying to make it sound different from “cling on”. But the -IN pronunciation never clung on.