Vortigaunts are interesting critters. In Half-Life 1, you're required to kill gads of necklace-wearing vortigaunts in order to save the world. All the while, there's a rumor going around that those aren't necklaces, they're control devices. The rumor goes that vortigaunts aren't bad guys, they're just being controlled by bad guys.
Then you play Half-Life 2. Vortigaunts are nice now. They almost seem to suck up to you. One even zaps you, just like in the old days, but this time it charges your HEV suit instead of killing you. That's a pretty big difference! Oh, and no necklaces. Coincidence? Could be.
One thing that I've really enjoyed about the Half-Life series is that the developers don't care if you cheat. Not in single player, anyway. If you cheat online, then you're going to get kicked off of the online servers for five years, but cheating alone is ok. I think this is a healthy attitude.
I enjoy cheating (after I've played the game a couple of times without cheating) because it allows me to explore and try new things. I like being able to walk right up to an airborne hunter-chopper and fire 42 consecutive RPGs at it, bringing it down in a flaming heap of junk metal. I like popping the Civil Protection guards in the train station at the beginning of the game with my nine millimeter, just because they're ugly and short-tempered. Walking through walls is nice. It's a handy trick when you just want to get through a given area quickly. It's also nice to get face-to-face with characters that you usually only get to see from a distance, like Ravenholm's Father Grigori.
Speaking of Grigori, a shotgun in Half-Life 2 is extremely useful long before he gets around to giving you one. And speaking of weapons, where are my det packs? Det packs are very handy indeed. And a gluon gun sure would be useful.
Anyway, in my cheating, I've found a vortigaunt in Black Mesa East who has plenty to say about the relationship between Gordon and the vortigaunts. You have to walk through a chain link fence to get to him. I found later that there's a vortigaunt at the end of the canals level who you don't have to cheat to get to (I did anyway), and who says the same things. He also makes some noises as you're approaching him to let you know to keep walking through the radioactive goo that makes him hard to get to. He says:
"Hurrrmmmmmmmmmmmmmmmmmmmm. Durrrrrrrrrrrrrrr. Churrrrrrrrrrr---Koff! Hack! Wheeze!"
Then once you get face-to-face with him and start talking, he says the same things as the Black Mesa East Vortigaunt.
Now as far as the vortigaunt's voice, Valve coughed up a really talented voice actor. If you can imagine Yoda plus James Earl Jones minus Kermit the Frog, you've just about got the vortigaunt's voice. His voice is deep, gravelly, emotional, and he stretches out words for intensity. So when he says "Your bright face obscures your darker mask!" it sounds like this: "Your (higher) bright face (normal) obscures your (low and slow) darrrrker masssssk!"
Listed below are all the responses I could get out of these two vortigaunts. I had game captions turned on while I played to help with transcribing, but sometimes the vortigaunt doesn't say the captions exactly, and I've favored what's actually said rather than what's written on the screen. Here they are:
We remember the Freeman. We are coterminous.