Case is the grammatical function and a form of a noun or pronoun, showing its relationship to other words in a sentence. There are three cases.
Subjective case: I, you, he, she, it, we, and they
Objective case: me, you, him, her, it, us, and them
Possessive case: my, your, his, her, its, our, and their
Knowing which case a pronoun belongs to is to use the right pronoun in a sentence. If a pronoun is used as the subject of a sentence, a pronoun in the subjective case is used; if a pronoun is used as an object in the sentence – direct object, indirect object, and object of preposition – a pronoun in the objective case is used; and if a pronoun is used to show ownership, a pronoun in the possessive case is used.



Subjective and objective cases

A noun does not change its form whether it is used in the subjective case or the objective case.

  • The husband called the wife.

    (The noun husband is the subject of the sentence.)

  • The wife called the husband.

    (The noun husband is the direct object in the sentence.) 




A pronoun has different forms when it is in the subjective case or the objective case.

  • I bought a bun for my sister.

    (The subject is I, the direct object is bun, and the indirect object is sister.)

  • My sister bought a bun for me.

    (The subject is sister; the direct object is bun; and the indirect object is me.) 

As is seen, the nouns bun and sister do not change; only the pronoun changes. The subjective pronoun I becomes the objective pronoun me when it is used as an object. 




Errors occur when pronouns in the wrong cases are used:

  • Incorrect: George and me caught some crabs.

    (George and me are used in the subjective case, but me is an objective case pronoun. The subjective case pronoun I should be used instead.) 

  • Correct: George and I caught some crabs. 

  • Incorrect: My brother gave a lift to my father and he.

    (The pronoun he is a subjective case pronoun but is used here as an objective pronoun.)

  • Correct: My brother gave a lift to my mother and him.

    (The pronoun him is correctly used here in the objective case.) 


The possessive case
Pronouns in the possessive case show possession (ownership) of someone or something. They are personal pronouns in the forms of possessive adjectives, also called possessive determiners – first person: my, our; second person: your; third person: his, her, its, their. A possessive adjective comes before a noun that it modifies in the sentence. It shows to whom the noun belongs. A possessive adjective is not a possessive pronoun.



  • Incorrect: The pangolin is mine pet.

    (The word mine is a possessive pronoun and it is incorrectly used before a noun.) 

  • Correct: The pangolin is mine.

    (The possessive pronoun mine is correctly used in place of the noun pet.) 

  • Correct: The pangolin is my pet.

    (The possessive adjective my is correctly used before a noun.) 



Catenative verb
A catenative verb is a verb that is followed directly by another verb. The verb that follows is usually in a non-finite form. The second verb that follows a catenative verb can be a to-infinitive, bare infinitive, or present participle (verb+ing) / gerund form. 
The second verb is to + infinitive, and, together with all the words that follow, can be described as the direct object of the first verb.



  • We tried to reach home before it rained.
    (The catenative verb tried is followed by the to-infinitive to reach.)
  • They expect to win this game.
    (The catenative verb expect is followed by the to-infinitive to win. To each home before it rained in the first sentence and to win this game in the second sentence are direct objects of the verbs tried and expect.)  


The catenative verb that is followed by a bare infinitive is typically a modal verb such as can, could, will, would, shall, should, must, and ought The noun husband is the direct object in the sentence.)


 followed by verb+ing/gerund.



  • His parents love birdwatching.
  • I always enjoy lying on the beach.



A clause is a group of words including a verb. One clause is a simple sentence.
A complement is an adjective or a noun phrase that follows a linking verb such as be, and it gives more information about the subject. There are adjective complement, object complement, and subject complement. 
Complex sentence
A complex sentence consists of one independent clause and at least one dependent clause. These two clauses are joined using a subordinate conjunction.
  • While you were away, I fed your goldfish and hamsters.
The independent clause is I fed your goldfish and hamsters, which is also called a main clause. While you were away is the subordinate clause introduced by the subordinating conjunction while.
Compound sentence
A compound sentence consists of two or more independent clauses. This means a compound sentence cannot have a subordinate clause. There are three ways that the two independent clauses can be joined to form a compound sentence.
Using a coordinating conjunction (for, and, nor, but, or, yet, so): Donkeys and monkeys are animals.
Using semi-colon (;): That’s the house for sale; there’s a small pond in the backyard.
Using a conjunctive adverb: The new mall has grocery stores, movie theatres and restaurants; furthermore, it is within walking distance.
Compound-complex sentence
A compound-complex sentence consists of at least two independent clauses and at least one dependent clause.
  • She told me to keep quiet, but I wouldn’t until I had said all the things I wanted to say.
Independent clauses: She told me to keep quiet and but I wouldn’t; dependent clause: until I had said all the things I wanted to say.


Compound verb
A compound verb is a combination of two or more verbs that function as a single verb of a single subject of a sentence. The two or more verbs are connected by coordinating conjunctions. Coordinating conjunctions are for, and, nor, but, or, yet, and so (fanboys). A compound verb is used when a subject is doing more than one thing. Using a compound verb  cuts down the number of words used in a sentence and avoids repetition.
In each of the following sentences, the subject has more than one verb (in bold) which is called a compound verb.



  • She said there were ghosts in the kitchen, for she saw them.
  • He punched his younger brother and kicked him on the knee.
  • They neither know nor care what she said about him.
  • support the home team, but bet it will lose.
  • You can come along or stay at home.
  • The team played very well, yet lost the match.
  • She felt insulted by him, so she slapped his face.


The types of compound verbs include prepositional verb, phrasal verb, verb with auxiliaries, and single-word verb.

Prepositional verb
A prepositional verb is created with the combination of a verb and a preposition. They must not be separated in a sentence with a word or phrase coming between them.



  • A tile fell off the roof.
  • The building burned down last month.
  • He bumped into me from behind.


Phrasal verb
A phrasal verb is a combination of a verb and a word from another part of speech. Together, they form a new verb with a different meaning from that of each of the two words that make up the phrasal verb. 



  • Our meeting came about by accident.
  • Someone broke into their house while they were away.
  • The bank robbers made off before the police arrived.


Verb with auxiliaries
A verb with auxiliaries is typically a main verb and an auxiliary verb or helping verb (am, is, are, was, were, have, has, had, be, been) followed by another verb.



  • She is lying on the beach.
  • We are preparing for the trip.
  • They will be arriving in an hour’s time.


Compound single-word verb
A compound single-word verb is a compound verb of more than one word acting as a single verb. It may be connected by a hyphen, or a combination of two words acting as a one verb.



  • We cherry-pick the television programs to watch.
  • She used a lot of oil to deep-fry the chicken.
  • She sunbathes every week.
  • They honeymooned in Antarctica.



Conditional conjunction
Conditional conjunctions are used to show that something will happen on the condition that something else happens or to describe a hypothetical or unreal situation. This is done by making one clause in a sentence subordinate to or dependent on another clause within the same sentence. This subordinate/dependent clause is the conditional clause, while the clause it depends on is an independent clause. Such a sentence is referred to as a conditional sentence as it contains a conditional clause.


The conditional clause is introduced by a conditional conjunction, most commonly if or unless.  Such a clause either goes before or follows the independent clause, which is also called the main clause. 

Conditional conjunctions include after, as long as, as soon as, assuming that, because, before, despite, even if, if, if only, in case, in order, now that, provided, providing that, shouldsince, supposing, therefore, unless, until, when, whenever, wherever, whether or not, and yet.
Examples of sentences containing conditional conjunctions



The subordinate clauses are in bold. A comma is used when a subordinate clause comes earlier.

  • You won’t get cancer so soon as long as you smoke moderately
  • As long as you smoke moderately, you won’t get cancer so soon. 
  • I will be glad to do it if you want me to eat the whole cake
  • If you want me to eat the whole cake, I will be glad to do it. 
  • You can join the drinking session provided you don’t get yourself drunk
  • Provided you don’t get yourself drunk, you can join the drinking session.  
  • Should you feel sea sick, you could lie in the cabin. 
  • Since it is quite late, the hardware shop is not open. 
  • You will not go for dinner with me unless you pay for it




The conditional conjunction if, used to express a hypothetical statement, can be removed without affecting the meaning of the sentence.

  • If you had tasted my beef soup, you would know how creamy it was.
  • Had you tasted my beef soup, you would know how creamy it was.
  • If the rescuers found them within the first week, most of them would be alive.
  • Were the rescuers to find them within the first week, most of them would be alive.