Word class membership:

Although the caption above may give the impression that any one word within a single meaning belongs exclusively to one word class, you should note that this is not the case. Study the words in bold in the following examples:

·         I could not give her an immediate answer.

·         I was surprised when he answered my letter.

·         Do not write on the front of the answer sheet.

·         In the first sentence, answer is being used as a noun – note the attributive adjective immediate and the word an, both indicative of a following noun.

·         In the second, answer is a verb – the subject he and the ending –ed­ show this.

·         While in the third, answer tells you what kind of sheet is being talked about and is, therefore, an adjective.

This flexibility in word class membership is a peculiar feature of English among the European languages, many of which would require different endings to show the class of the word.

Some words belong to more than one part of speech. We can’t know what part of speech a word is until we see what work it is doing in a sentence. A word can do different jobs in different sentences. 

Look at the following sentences. 

1. Give me some water. 
2. They water the plants daily. 

In the first sentence the word WATER names something. So it is a noun. 
In the second sentence the same word WATER expresses an action. It tells what they do. Here it is a verb. 

Study the word FAST in the following sentences. 

1. He didn’t take anything during the fast. (It names something. So it is a noun.) 
2. Muslims FAST during Ramazan. (It expressess an action. It tells what Muslims do. So, it is a verb.) 
3. I missed the FAST train. (It adds to the meaning of the noun train. What kind of a train? A fast train. So, it is an adjective.) 
4. She speaks fast. (It adds to the meaning of the verb SPEAKS and tells how she speaks. So, it is an adverb.) 
The word FAST is a noun in 1, a verb in 2, an adjective in 3 and an adverb in 4. 

Here are further examples. 
Above: 
We flew above the clouds. (Preposition) 
Have you read the above sentence? (Adjective) 
See above. (Adverb) 

Back: 
I have a pain in the back. (Noun) 
I will come back in five minutes. (Adverb) 
Have you closed the back door? (Adjective) 
He backed his car through the gate. (Verb) 

Better: 
This watch is better than that. (Adjective) 
He singes better than you. (Adverb) 
You should respect your betters. (Noun) 
Living conditions have bettered a great deal. (Verb) 

Down: 
The little girl feels down. (Adverb) 
He ran down the hill. (Preposition) 
We caught the down train. (Adjective) 
The government downed the opposition. (Verb) 

Like: 
Children like sweets. (Verb) 
He climbs like a cat. (Preposition) 
You won’t see his like again. (Noun) 
Tashi and his brother are very like. (Adjective) 

Near: 
He lives near the station. (Preposition) 
Most of my near relatives live abroad. (Adjective) 
He got nervous as the examinations neared. (Verb) 
I went near enough to see over it. (Adverb) 

Right: 
You are quite right. (Adjective) 
Keep to the right. (Noun) 
Go right to the end of the road. (Adverb) 
They were able to right the boat. (Verb) 

Round: 
The earth is round. (Adjective) 
The boys ran round the tree. (Preposition) 
Will you come round to our house this evening? (Adverb) 
We won the first round of the tennis cup. (Noun) 
The child’s eyes rounded with excitement. (Verb) 

Up : 
You should stand up when the teacher comes in. (adverb) 
He climbed up the hill. (Preposition) 
What time is the next up train? (Adjective) 
He hit the ball on the up. (Noun)