Embedded clauses may be further subclassified according to their function within the superordinate clause. Here, syntactic and semantic criteria may overlap or coincide. Possible subdivisions at this level are the following:
Nominal clauses can function in some or all of the noun phrase functions, such as Subject, Object, Complement, etc. These include that-clauses, interrogative clauses and gerundive (-ing) clauses, as in 59:
| (59) | [S [NP He NP] [VP enjoys [CL-NOM playing practical jokes CL-NOM] VP] . S] |
Adverbial clauses function mainly as adjuncts. Semantically, they distinguish approximately the functions that adverbs show, as in 60:
| (60) | [S [NP We NP] [VP left [CL-ADV after the speech ended CL-ADV] VP] . S] |
Comparative clauses resemble adjectives and adverbs in their modifying functions, as in 61:
| (61) | [S [NP He NP] [VP is as clever [CL-COMP as I thought CL-COMP] VP] . S] |
A relative clause generally functions as a modifier of a noun, as in 62:
| (62) | [S [NP The book [CL-REL that I bought yesterday CL-REL] NP]. S] |