In linguistics

Linguistics

Linguistics is the scientific study of human language. Linguistics can be broadly broken into three categories or subfields of study: language form, language meaning, and language in context....

, subordination (abbreviated variously , , or ) is a complex syntactic construction in which one or more clause

Clause

In grammar, a clause is the smallest grammatical unit that can express a complete proposition. In some languages it may be a pair or group of words that consists of a subject and a predicate, although in other languages in certain clauses the subject may not appear explicitly as a noun phrase,...

s are dependent on the main clause, such as The dog ran home after it had played with the ball. The italicized text is the subordinate clause. The grammatical structure associated with subordination is hypotaxis

Hypotaxis

Hypotaxis is the grammatical arrangement of functionally similar but "unequal" constructs , i.e., constructs playing an unequal role in a sentence....

, or the grammatical arrangement of "unequal" constructs (hypo="beneath", taxis="arrangement".

Dependent clause

Dependent clause

In linguistics, a dependent clause is a clause that augments an independent clause with additional information, but which cannot stand alone as a sentence. Dependent clauses modify the independent clause of a sentence or serve as a component of it...

s are also called "subordinate clauses".

Subordinate clauses are introduced by a complementizer

Complementizer

In linguistics , a complementizer is a syntactic category roughly equivalent to the term subordinating conjunction in traditional grammar. For example, the word that is generally called a complementizer in English sentences like Mary believes that it is raining...

 (e.g. that, if, whether) or a subordinating conjunction (e.g. after, because, while).

• subordinate complement
  Complement (linguistics)
  In grammar the term complement is used with different meanings. The primary meaning is a word, phrase or clause that is necessary in a sentence to complete its meaning. We find complements that function as an argument and complements that exist within arguments.Both complements and modifiers add...
  
   clause: I don't know if George is awake yet.
• subordinate modifier
  Grammatical modifier
  In grammar, a modifier is an optional element in phrase structure or clause structure; the removal of the modifier typically doesn't affect the grammaticality of the sentence....
  
  clause: George overslept because his alarm clock was broken.