During, however, is syntactically pickier. It does not allow for a clausal complement

Some exocentric compounds don’t have an interpretive head, but still have what we might call a category head, in that the root on the right matches the category of the whole compound. For example, redhead (“person with red hair”) is often listed as an exocentric compound, because it does not describe a type of head. Similarly sabretooth is exocentric because it doesn’t describe a type of tooth. But both of these are noun-noun compounds that are themselves nouns, so their right-hand member is almost a head. A spoilsport (“person who spoils other people’s fun”) is not a type of sport, but it is still a noun.

1.  How flexible are these category heads in exocentric compounds?

If the active and passive articulators are very close but not touching, creating a narrow constriction, airflow through this constriction becomes very turbulent, resulting in highly random noisy airflow called frication, which sounds like hissing or buzzing. A phone articulated this way is called a fricative. The English words set and vet begin with fricatives.

Computer languages are not usually the focus of linguistics, even though many linguists use them to analyse linguistic data!