Phrases, Clauses, and Sentences

How is a long sentence formed? (Or, how do you simplify a sentence?)


1.      Words are added to existing words so as to add more meaning to what one wants to say.

2.      We add adjectives to modify nouns, adverbs to modify verbs or adjectives, etc.

3.      The reverse direction, removing words from a sentence, makes the structure of a sentence more apparent.

Exercise. Add words to modify a simple word “”. Repeat the action 20 times.

Exercise. Add words to modify a simple sentence “他吃”. Repeat the action 20 times.


Sentences (A First Attempt)


1.      Sentences are the basic building blocks of paragraphs and articles. Analyzing sentence structure is very important and yet difficult for students learning English.

2.      A bare bone sentence = S + V. (S = subject 主詞, V = main verb.) All other words in the sentence serve to modify or describe S, V, and other parts of the sentence.

3.      Finding S and V, you are half way through with analyzing a sentence.

4.      The subject of a sentence can be a noun or other structures (phrases and clauses). It is usually placed in the beginning of a sentence and before the main verb. If possible, narrow it down to a single, most important word.

5.      The main verb must be 原形動詞, or in third-person-singular or past tense. Finding the main verb is complicated by the presence of other verbs (in many different forms) in a sentence.

6.      Hence, we need to delve into phrases and clauses.




1.      A phrase is defined to be one or more words that function as a unit within a sentence. A phrase may consist of only one word.

2.      Phrases do not have complete S+V structure. (Clauses do.)

3.      Important types of phrases: prepositional phrases, infinitive verbal phrases, participial verbal phrases.

4.      Prepositional phrase = prep. + object (noun, gerund, clause, etc.)
Examples: in the morning, over the fence, by comparing the values.

5.      Infinitive verbal phrase = to+V + other words.
Examples: to compute the mean, to be able to move around.

6.      Participial verbal phrase = (Ving or Ven) + other words.
Examples: comparing the values, calculated risk.

7.      Verbal phrases contain verbs in nonfinite(不限定) forms: to+V, Ving, and Ven.




1.      A clause is a group of words that go together and have a subject and a “main verb”.

2.      The main verb in a clause must be in a finite(限定) form: present or past tense, with or without auxiliary verbs. It cannot be Ving, Ven, or to+V. Depending on the tense and voice, a clause may contain other verbs in inflected forms. For example, in “I am reading a book”, “am” is the main verb; but “reading” is also part of the verb structure.

3.      In the last example, we say “am” is the verb required by the English grammar(文法上或形式上的主動詞), while “reading” is the verb describing the actual action(意義上的主動詞). In some cases, such as in simple present tense, 文法上及意義上的主動詞are the same.

Exercise. For each possible combination of persons, tenses, voices, and presence of auxiliary verb, write down a short sample sentence and point out

4.      Independent clauses are complete clauses that can stand alone as sentences.

5.      Dependent clauses cannot stand alone as sentences but must be attached to independent clauses. A dependent clause is signaled by having (1) a conjunction, such as “although”, and “because”, or (2) a relative pronoun, relative adjective, or relative adverb, such as “that”, “which”, and “where”.


Sentences (Revisited)


1.      There are three types of sentences: simple sentences, compound sentences, and complex sentences.

2.      simple sentence = one independent clause

3.      compound sentence = two independent clauses

4.      complex sentence = one independent clause + one dependent clause(s)


Official Steps in Analyzing Sentences


1.      Determine if the sentence is a simple, compound, or complex sentence. For a simple sentence, do Steps 2-4 below. For a compound sentence, do Steps 2-4 for each clause. For a complex sentence, do Steps 2-4 first for the independent clause, then for the dependent clause(s).

2.      Locate S+V. Use as few words as possible in the subject. For the verb part, make sure you point out both 文法上及意義上的主動詞。Translate the result into Chinese.

3.      Add words that are left out from previous steps Do it slowly. Each time add only a few words that logically belong together. Also, translate the result into Chinese. You can also use different color to highlight the newly added parts.

4.      Repeat step 2 until you get the original sentence back. At this time, you should have a complete translation of the original English sentence. You may choose to rephrase the translation to make it smoother.

5.      You should follow these steps in each of your “Weekly Sentence” assignments. You can click the following links ((1), (2), (3), (4), (5), (6), (7), (8), (9)) to see some sample sentences from last semester. Note that last year I didn’t ask the students to analyze sentence type.