Does English support three-word contractions?
In English certain pairs words can be contracted with an apostrophe, such as "I've" (I have). I don't know if there are strong rules for which words can be combined in this way and which can't. In all the examples I can think of, each contributing word is only one syllable.
Does any version of English formally recognize combining three words like this as being normative, as opposed to considering it incorrect or slang (as one might find on Twitter or Usenet)? I imagine it'd depend on which words, just as combining two words seems to. I just found myself writing "I'd've" (I would have), and I wouldn't've thought much of it, but a non-native speaker asked me about this construction and I don't know whether it's personal quirk, a marker of a certain type of population, or normative.