I notice the word “so” used frequently in a context such as this:
“I am sooo ready”
Is there a name for this type of speak such as Valley girl?
Wasn’t this popularized on the TV show Friends? Friendspeak?
I vote for ‘annoying’.
Even worse is the negative form.
“I am sooooo not buying that.”
More specifically, it’s Chandlerspeak.
Tomato / tomahto.
I am pretty sure that on Friends, they were just speaking like normal people of that demographic already do. They didn’t invent anything.
Unless I’m misreading the OP, that’s not Chandlerspeak.
Chandlerspeak would be “I am so not buying that.”
OK thank you everyone. I wasn’t familiar with the TV program mentioned so I Googled it.
I so totally agree with Gagundathar. It is anoying even to a non-native speaker.
What’s the difference between “so” and “sooo”?
I mean, I know that an underline and italics are two different ways of showing emphasis in text, but other than that you lost me!
Sooo implies, to my mind at least, that the word is drawn out (and given emphasis via the italics), where as simply so or so implies emphasis without the word being drawn out.
The differences are in context, too. CBEscapee’s example is just emphasizing a word that’s already used to emphasize a statement. Chandler’s use is kind of ironic, because it’s not common (didn’t used to be) to use a positive emphasis on a negative statement.
I am definitely not buying that.
This was what I intended.
Right; it’s not the positive emphasis per se that is (or was) unusual, but the word “so”, which used to be just for modifying adjectives or other adverbs, not for modifying verbs.
Imagine a 1990s remake of the 1960s Blood, Sweat, and Tears song: “You so make me…very happy” 
Chandlerspeak wouldn’t be “I am so not buying that.”
It would be “I am so not buying that.”
I agree.
I respectfully disagree with this - I think the writers of “Friends” invented at least a couple of ways of speaking that have become mainstream. The “Friends” cast was my demographic, and we loved the new things that Chandler said (his other most popular one - “Could I BE any more innovative?”).
It’s a prosodic vowel modification.