A CLAUSE is a collection of grammatically related words including a predicate and a subject. A collection of grammatically related words without a subject or predicate is called a phrase.
The word group teacher both students and is not a phrase because the words have no grammatical relationship to one another. Similarly, bay the across is not a phrase. In both cases, the words need to be rearranged in order to create phrases. The word groups both teachers and students and across the bay are both phrases. Attributive adjective precedes noun. ‘both’ being an adjective, noun must follow ‘both’. Similarly ‘across’ is a preposition and hence must be followed by a noun or pronoun phrase.
Phrases can be noun, gerund, infinitive, predicate (verb phrase), adjective, or adverb.
Phrase: children playing in the park; Clause: children playing in the park are visible from the balcony; Clause: (You) Run! [Note that the subject is sometimes implied.]
Clauses are the building blocks of sentences: every sentence consists of one or more clauses. If a clause can stand alone as a sentence, it is an independent clause, as in the following example:
Independent clause and Subordinate (Dependent Clause)
‘I reached hostel.’ is an Independent Clause with a subject and predicate. Now consider the same clause preceded by the subordinating conjunction when as in when I reached hostel though this clause also has a subject and a predicate. Such a clause cannot stand alone as a sentence since the conjunction when suggests that the clause is providing information regarding time about an event and therefore must therefore be an adjunct to another clause. As this dependent clause answers the question when? just like an adverb does, it is called a dependent adverb clause. Note that this clause can replace the adverb early in the following example:
Adverb: The warden left early.
Adverb Phrase: The warden left before time.
Subordinate Adverb clause: The warden left when I reached the hostel.
Examples of other such Subordinate Clauses are of the following type. These are also called Embedded Clause, since these are embedded in the main matrix clause.
Noun: I know the route.
Non-finite Noun Clause: I know how to reach.
Subordinate Embedded Noun Clause: I know how we can reach faster by a shorter route.
Noun Complement Phrase (Prepositional): A change in direction of cyclone is likely in next six hours.
Noun Complement Phrase (Infinitive):There is no need to panic.
Noun Complement Clause: The fact that the planet is getting warmer is no longer debatable.
Adjective Complement Phrase (Prepositional): She is skilled at archery.
Adjective Complement Phrase (Infinitive): The children are eager to go.
Adjective Complement Clause: She is glad that you came. The witness is unsurewhether that was the voice of the alleged culprit.
Adjective Participial Phrase: The girl sitting at the left end of the row is our class topper.
Relative Adjective Clause: The gentleman who spoke last is the Dean of our Physics Department
Relative Adverb Clause: The reason why I want to skip lunch is that I had late and heavy breakfast.
Cleft Sentence with Relative Clause: It is the irregularity of time in sleeping and eating which made me sick.
Comparison Prepositional Adverb Phrase of unequal value: He is not strong like his brother.
Comparison Adverb Clause of unequal value: His brother is more rigid and headstrong than he is.
More on Independent Clause
Independent clauses are joined by coordinating conjunctions which are: for, and, nor, but, or, yet, so (popularly known as FANBOYS)
Additive of affirmatives: He mopped the floor, and I washed the clothes.
Additive of Negatives : I didn’t sleep, nor did I finish the homework.
Disjunctive : You can rest, or you may watch a movie.
Effect>Cause : I need to leave, for children are about to reach home.
Cause> Effect : Children are about to reach home, so I need to leave.
Contrast : He came late, but he finished his work.
Contrast with Emphasis: He came late, yet he was the first to finish.
Other conjunctions which coordinate Independent Clauses are Correlative such as: either ...or, neither...nor, both...and, not only... but also, as....as.
He is not as strong and stout as his brother is.
He is both an accomplished guitarist and an ace singer.
Independent Clauses are mainly of six types:
Declarative: Delhi is capital of India; She has no idea; Here it rains in winter; There is no water; We must hurry; I wish you were there
Interrogative: Is this your car? Where had you been so long? Which number should I dial for room service?
Imperative: Let’s go; Let’s go for a long drive; Let him wait; Don’t go; Don’t you ever use staff toilet; Have some more cake and pastry
Exclamative: What a beautiful painting it is! Didn’t she dance so well! How helpful you have been!
Benedictive (blessing): May the Force be with you always. May you be blessed with a son.
Maledictive (curse): "Blessed be the man that spares these stones, And cursed be he that moves my bones." [2nd part is maledictive and 1st part is benedictive. This is the Epitaph of William Shakespeare]
More on Dependent/ Subordinate Clause
According to modern grammar, a Clause cannot be a noun or adjective or adverb unlike Phrases. A phrase can be noun or adjective depending upon whether head of the Phrase is Noun or Adjective. Similarly an Adverb/Adjunct is either a single word or (e.g.: he will come tomorrow) or a prepositional phrase (e.g.: He will come after Monday). A Clause however doesn’t have any such head. It is just like any independent clause with a marker.
Therefore traditionally what we call a Noun Clause is nothing but an adjunct which is Prepositional Phrase where prepositions are different from those used before a noun phrase or pronoun or gerund. The following example endorses this argument as professed in modern grammar.
I had vomiting and loose motion because of stomach infection.
I had vomiting and loose motion because I had stomach infection.
‘because of’ is a preposition followed by a noun phrase and according to modern grammar ‘because’ is a preposition followed by a Content Clause. In traditional grammar ‘because’ is a subordinating conjunction and the clause is termed a ‘noun clause’ as an equivalent of noun phrase after normal preposition. Some call the clause along with the conjunction as an Adverbial Clause.
Similarly what is Adjective Clause and Adverb Clause in traditional grammar, is termed Relative Clause in modern grammar.
Adverbials with Clause for comparison take Comparison Clause which is different from Content Clause.
A Content Clause as evident needs a MARKER and it can be used to function as an adjunct or modifier (as an adjective/ adverb) or complement. This Marker is a preposition when used as an adjunct or THAT when used as complement of verb or noun or adjective or Wh-word when used as an embedded question or as a complement of adjective.
[Reference: http://www.lel.ed.ac.uk/~gpullum/FiniteSubordinateClauses.pdf]
Example of complex sentence with more than one subordinate clause:
Rather than sleeping early, he worked till it was late in the night though he was to wake up early to catch the flight.
Phrase Type by Grammatical Function of Head of Phrase
Example 1
Cycling is exhausting.
[Gerund subject + Verb + Predicate Adjective]
Cycling to factory is exhausting.
[Gerund subject + Adverbial Phrase of Place + Verb + Predicate Adjective]
Cycling to factory when it is hot and humid is exhausting.
[Gerund subject + Adverbial Phrase of Place + Adverbial Clause of Time + Verb + Predicate Adjective]
Cycling to factory when it is hot and humid is very exhausting.
[Gerund subject + Adverbial Phrase of Place + Adverbial Clause of Time + Verb + Adverb + Predicate Adjective]
Notice that the Gerund ‘Cycling’ remains the head of the Gerund Phrase ‘Cycling to factory when it is hot and humid’
Similarly ‘exhausting’ is head of the Adjective Predicate Phrase ‘very exhausting’
Head of a phrase can stand independently without modifiers and can still retain its grammatical function.
Without modifiers, a phrase or clause cannot have a head as in the case of Adverbial Phrase of Place and Adverbial Clause of Time, above.
Example 2
Sameer is planning.
[Noun + Verb]
Sameer is planning to change.
[Noun + Verb + Infinitive Complement]
Sameer is planning to change job.
[Noun + Verb + Infinitive Complement + Object Noun of Verb]
Sameer is planning to change job after completion.
[Noun + Verb + Infinitive Complement + Object Noun + Adverbial Phrase]
Sameer is planning to change job after completion of course.
[Noun + Verb + Infinitive Complement + Object Noun + Adverbial Phrase + Noun Complement]
Sameer is planning to change job after completion of certificate course.
[Noun + Verb + Infinitive Complement + Object Noun + Adverbial Phrase + Noun Complement Phrase with Noun Modifier]
Notice how ‘planning’ as head of the Verb Phrase retains its functional character of a Verb even as the Phrase keeps expanding with complements and other phrases.
Similarly ‘to change’ is the head of the Infinitive Phrase ‘to change.....course.’
‘completion of certificate course’ is a Noun Phrase with abstract action noun ‘completion’ as the head.
To conclude, a phrase type can continue to expand with Modifier Phrase/ Clause and Complement Phrase/Clause - further expanded by modifiers and complements.