Complement and Adjunct: The Difference

Both complements and adjuncts are elements of a clause structure according to the grammatical model of the systemic functional grammar. As independent elements of a clause structure, they perform different roles that serve as yardsticks in distinguishing between both elements —however, they often pose a hard nut to crack for some persons when they are faced with the task of distinguishing between both elements and that is what this article seeks to tackle. 

Complement 

Now the complement element and the adjunct element are distinct elements of a clause structure that are not to be interchanged for each other and you will be seeing why shortly. The complement element is represented by two groups namely; The nominal group, and the adjectival group. Remember, groups are words or strings of words that function as a whole unit, having at least a headword, or a headword and both modifier and qualifier elements in it.

Some examples of the nominal group include:

1. The book

2. She

3. The man on the roof

4. Singing with a loud voice

5. You yourself with the flute

Some examples of adjectival groups include;

1. Hard

2. Harder than iron

3. Quite strong

4. Much faster than I expected

5. Smart enough

Now that you have seen their examples in isolation, here is how they function in clauses. For example;

1. I saw the grey car. (Nominal group as complement)

2. I am amazed. (Adjectival group as complement)

3. Mr. Gregory is the principal. (Nominal group as complement)

4. She ran faster than I had imagined. (Adjectival group as complement)

Note, also, the positional occurrence of complements. Complements are known to appear directly after the predicator element of a clause structure. This is because, complements in most cases give information about the attributes or qualities of the subject, while in other cases, they indicate the receivers of an action.

Adjunct 

Adjuncts on the other hand are quite a unique set of elements of a clause structure and you will find out why this is, in the foregoing.

Adjuncts are represented by groups such as: Nominal groups, Adverbial groups and Prepositional groups. Note, since, I already gave examples for nominal groups in the section on complements, I would not be repeating same here since the structure remains the same. So we will start with adverbial groups. For example;

1. Quickly

2. Smartly enough

3. Quite smoothly

4. Almost smoothly than expected

Some examples of prepositional groups include:

1. On the floor

2. In the jungle

3. At the party

4. With the drinkards

Now that you know the groups in isolation, here are examples of them in association or in a clause structure:

1. I am going to the store now. (Adverbial group as adjunct)

2. It is not this evening. (Nominal group as adjunct)

3. It is on the lawn. (Prepositional group as adjunct)

4. It happened yesterday. (Nominal group as adjunct)

5. He ate quickly. (Adverb as adjunct)

6. Donnie is at the dinning. (Prepositional group as adjunct)

You would notice that the adjunct elements of the clause structures above answer one or more of the following questions: Where? When? How? Why? To what extent? They give circumstantial information about the subject of a clause. Also, a very unique attribute of adjuncts is that they are the most mobile elements of a clause structure. What this implies is that they can appear anywhere in a clause either at the initial, medial or final position. 

At the intial position:

1. On the table, a cup dropped.

At medial position:

2. He is very happy.

At final position:

3. It is by the door.

So the the differences between complements and adjuncts is that, first, complements can only appear right after the predicator elements in a clause structure i.e. the verbal group, while adjuncts can appear almost anywhere. Before the subject, before the predicator, at initial positions, medial and final positions in a clause, you can find adjuncts at several positions. Also based on function, complements give information about the subjects of a clause and other times, indicate the receivers of the action of the subject (object), while adjuncts are committed to giving exclusive circumstantial information about subjects, or even clauses. Complements cannot be removed from clauses without altering meaning, while adjuncts can be easily removed without drastically altering the meaning of a clause structure.

Related posts:

• Clause Structure in SFG: What you should Know 
• Groups in SFG: What you need to Know 
• Adjectival groups in SFG
• Adverbials: Adverbs, Adverb Phrases, Adverb clauses, and Prepositional Phrases 
• Types of Complements: Fully Explained