In generative grammar, embedding is the process by which one clause is included (embedded) in another. This is also known as nesting. More broadly, embedding refers to the inclusion of any linguistic unit as part of another unit of the same general type. Another major type of embedding in English grammar is Subordination. In the process of embedding sentences, there is a matrix sentence and two or more insert sentences. The INSERT sentences are embedded into the MATRIX sentence through the application of several T-rules, such as Relativisation, Complementation, etc.
Clauses that stand on their own are known as the root, matrix, or main clauses. However, in some sentences, there can be multiple clauses. The following sentences contain two clauses each:
Lucy said that Sam sang.
In this sentence, you have the root clause: [Lucy said that Sam sang], which has the secondary clause [that Sam sang] embedded inside it.
Archie wants Charlie to vote.
In this sentence, the clause [Charlie to vote], which has the subject Charlie and the predicate phrase [to vote], is embedded within the main clause [Archie wants Charlie to vote].
Both examples of clauses within clauses are embedded clauses. The following examples illustrate three types of embedded clauses.
Relative clause: The boy who came is his cousin. (who came)
Noun clause: I told him that I would go. (that I would go
Adverb clause: He left when the bell rang. (when the bell rang)
A Relative Clause is a type of subordinate clause, which functions as the modifier of the NP of the main sentence. There are two kinds of Relative Clauses, Restrictive RC and Non – restrictive RC. The restrictive RC is not separated by commas and is said as one tone group. The non – restrictive RC is divided into three tone groups separated by commas/pauses.
Restrictive RC limits the scope of the NP it modifies: The Chinese who live in Singapore are very lucky.
A non – restrictive RC merely provides additional information about the NP that it modifies: The Chinese, who belong to the Mongoloid race, have slit eyes.
A Noun Clause is a dependent or subordinate clause that works as a noun. It can be the subject of a sentence, an object, or a compliment.
An Adverbial Clause is a clause that works as an adverb in a sentence. Like all clauses, an adverbial clause has a subject and a predicate. However, an adverbial clause is a dependent clause- so, it can never be a sentence on its own. Specifically, an adverbial clause is a modifier that modifies the independent clause.
Thus the three types of Subordination Transformations are: