- Home
- 1. Introduction to time, tense and aspect
- 2. Past time
- 2.1 Past simple
- 2.2 Past continuous
- 2.3 The difference between the past simple and the past continuous
- 2.4 Past perfect
- 2.5 The difference between the past simple and the past perfect
- 2.6 Past perfect continuous
- 2.7 The difference between the past perfect and the past perfect continuous
- 2.8 Present simple to express past
- 2.9 USED TO for past habits
- Exercise 1
- Exercise 2
- Exercise 3
- Exercise 4
- Exercise 5
- 3. Present time
- 4. Future time
- 4.1 Future simple
- 4.2 Future continuous
- 4.3 Future perfect
- 4.4 Future perfect continuous
- 4.5 BE GOING TO
- 4.6 Present simple for fixed future events
- 4.7 Present continuous for fixed future arrangements
- 4.8 The difference between WILL, BE GOING TO and the present continuous for future events
- 4.9 Future time clauses
- Exercise 1
- Exercise 2
- Exercise 3
- Exercise 4
- Exercise 5
- 5. Modals
- 5.1 Types of modals
- 5.2 Modals to express ability: CAN, COULD, BE ABLE TO
- 5.3 Modals to express advice: SHOULD, OUGHT TO, HAD BETTER
- 5.4 Modals to express criticism: CAN, COULD, MIGHT, SHOULD
- 5.5 Modals to express deduction: MUST, CAN'T, COULDN'T
- 5.6 USED TO
- 5.7 Modals to express intentions: BE GOING TO, WILL
- 5.8 Modals to express obligation: MUST, HAVE (GOT) TO
- 5.9 NEED
- 5.10 Modals to express obligation: SHOULD, OUGHT TO
- 5.11 Modals to express offers: CAN, COULD, WILL, SHALL, MAY
- 5.12 Modals to express permission / prohibition: CAN, COULD, MAY, MIGHT, BE ALLOWED TO, MUSTN'T
- 5.13 Modals to express possibility: MAY, MIGHT, COULD
- 5.14 Modals to express predictions: BE GOING TO, WILL
- 5.15 Modals to express requests: CAN, COULD, WILL, WOULD
- 5.16 Modals to express suggestions: SHOULD, COULD, MIGHT, SHALL
- 5.17 The modal WOULD to express unreal situations
- 5.18 Overview of modals
- 5.19 Modals and adverbs
- Exercise 1
- Exercise 2
- Exercise 3
- Exercise 4
- Exercise 5
- 6. Conditionals and unreal tenses
- 7. Indirect speech
- 7.1 The difference between direct and indirect speech
- 7.2 Punctuation in direct speech
- 7.3 Changes in indirect speech
- 7.4 Reporting questions
- 7.5 Reporting statements
- 7.6 Reporting imperatives
- 7.7 Reporting verb + THAT-clause
- 7.8 Reporting verb + THAT-clause with SHOULD + infinitive
- 7.9 Reporting verb + THAT-clause with the present subjunctive
- 7.10 Reporting verb + gerund
- 7.11 Reporting verb + TO-infinitive
- 7.12 Reporting verb + object + TO-infinitive
- 7.13 SAY, TELL and ASK
- 7.14 Impersonal reporting
- Exercise 1
- Exercise 2
- Exercise 3
- Exercise 4
- Exercise 5
- Exercise 6
- Progress test 1
- 8. Passive voice and causative structures
- 8.1 Passive voice
- 8.1.1 The difference between the active and passive voice
- 8.1.2 Form: passive voice
- 8.1.3 Verbs which cannot be used in the passive voice
- 8.1.4 Ditransitive verbs in the passive voice
- 8.1.5 The agent with the passive voice
- 8.1.6 The use of the passive voice
- 8.1.7 The passive with GET
- 8.1.8 Passive voice with reporting verbs
- 8.2 Causative structures
- Exercise 1
- Exercise 2
- Exercise 3
- Exercise 4
- Exercise 5
- Exercise 6
- 8.1 Passive voice
- 9. Non-finite verb forms
- 9.1 The difference between finite and non-finite verb forms
- 9.2 The infinitive
- 9.2.1 The forms of the infinitive
- 9.2.2 The "subject" of the infinitive
- 9.2.3 The TO-infinitive to replace a relative clause
- 9.2.4 The TO-infinitive after passive reporting verbs
- 9.2.5 The infinitive after modals
- 9.2.6 DO, DOES, DID + bare infinitive
- 9.2.7 SEE, WATCH, HEAR, LISTEN, FEEL, SMELL, NOTICE + object + bare infinitive
- 9.2.8 APPEAR, HAPPEN, PROVE, SEEM, TEND, TURN OUT + TO-infinitive
- 9.2.9 HAVE, GET, LET, MAKE + object + infinitive
- 9.2.10 Verb + TO-infinitive
- 9.2.11 Verb + object + TO-infinitive
- 9.2.12 Adjective + TO-infinitive
- 9.2.13 The infinitive of purpose
- 9.2.14 The infinitive of result
- 9.2.15 Question word + TO-infinitive
- 9.2.16 Introductory infinitive clauses
- 9.3 The gerund
- 9.3.1 The forms of the gerund
- 9.3.2 The "subject" of the gerund
- 9.3.3 The gerund as subject
- 9.3.4 The gerund as a subject complement
- 9.3.5 The gerund as the object of a verb
- 9.3.6 Verb + gerund
- 9.3.7 Preposition + gerund
- 9.3.8 Verb + preposition + gerund
- 9.3.9 The gerund used in compound nouns
- 9.3.10 Other expressions followed by the gerund
- 9.3.11 Verbs followed by the TO-infinitive or gerund with no difference in meaning
- 9.3.12 Verbs followed by the TO-infinitive or gerund with a difference in meaning
- 9.4 The participle
- 9.4.1 The forms of the participle
- 9.4.2 The "subject" of the participle
- 9.4.3 The present participle used to form the continuous aspect
- 9.4.4 The past participle used to form the perfect aspect
- 9.4.5 The past participle used to form the passive voice
- 9.4.6 The present and past participles used as adjectives
- 9.4.7 SEE, WATCH, HEAR, LISTEN, FEEL, SMELL, NOTICE + object + present participle
- 9.4.8 CATCH, FIND, LEAVE + object + present participle
- 9.4.9 COME, GO + present participle
- 9.4.10 SPEND, WASTE + object + present participle
- 9.4.11 HAVE, GET + object + past participle
- 9.4.12 Participle clauses
- 9.5 The difference between the gerund and the present participle
- Exercise 1
- Exercise 2
- Exercise 3
- Exercise 4
- Exercise 5
- 10. Relative clauses
- 10.1 What is a relative clause?
- 10.2 Defining relative clause
- 10.3 Non-defining relative clause
- 10.4 The difference between defining and non-defining relative clauses
- 10.5 Sentential relative clause
- 10.6 Relative pronouns: WHO, WHOM, WHOSE, WHICH, THAT
- 10.7 Relative adverbs: WHERE, WHEN, WHY
- 10.8 Prepositions in relative clauses
- 10.9 Non-finite relative clauses
- 10.10 WHAT and WHATEVER
- 10.11 Cleft sentences
- 10.12 Pseudo-cleft sentences
- Exercise 1
- Exercise 2
- Exercise 3
- Exercise 4
- Exercise 5
- Exercise 6
- 11. Inversion
- 12. Articles and nouns
- 12.1 Articles
- 12.2 Countable and uncountable nouns
- 12.2.1 The difference between countable and uncountable nouns
- 12.2.2 Nouns with countable and uncountable meanings
- 12.2.3 Determiners with countable and uncountable nouns (SOME, ANY, NO, MANY, MUCH, FEW, LITTLE etc.)
- 12.2.4 Partitive expressions with uncountable nouns
- 12.2.5 Nouns which are always plural
- 12.2.6 Nouns with a plural form and a singular meaning
- 12.2.7 Nouns with the same singular and plural forms
- 12.2.8 Irregular plural forms
- Exercise 1
- Exercise 2
- Exercise 3
- Exercise 4
- Exercise 5
- Exercise 6
- Exercise 7
- Progress test 2
- Appendix
10.4 The difference between defining and non-defining relative clauses
A defining relative clause identifies or classifies a noun:
Do you know the guy who is talking to Will over there?
I wrote my essay on a photo which was taken by Robert Capa.
If we omit this type of clause, the sentence does not make sense or has a different meaning:
Do you know the guy? (which guy?)
I wrote my essay on a photo. (what kind of photo?)
A non-defining relative clause adds extra information about a noun which already has a clear reference:
The Mona Lisa was painted by Leonardo da Vinci, who was also a prolific engineer and inventor.
If we leave out this type of clause, the sentence still makes sense:
The Mona Lisa was painted by Leonardo da Vinci. (we know who Leonardo da Vinci was)
Sometimes, the use of commas marks a difference in meaning:
The athletes who failed the drug test were disqualified. (defining)
The athletes, who failed the drug test, were disqualified. (non-defining)
The defining relative clause tells us that only those athletes who failed the drug test were disqualified. The sentence implies that there were other athletes who did not fail the drug test and that they were not disqualified.
The non-defining relative clause tells us that all the athletes (mentioned earlier in the context) failed the drug test and that all of them were disqualified.