UNIT 3 Grammar rules

UNIT 3 Grammar rules

1. Modal Verbs

   • We use infinitive without to after a modal verb
     • You must wear a helmet
   • Modal verbs do not take -s in the third person singular
     • She must show her ID
   • We do not use the auxiliary do/does for negatives, questions,or short answers with must
     • She mustn’t take pictures
   • In American english, must and must not are used in formal, situation, especially rules

2. Verbs of obligation, permission, necessity, and prohibition

   • Obligation
     • We use have to when we want to talk about facts and external obligations
     • We usually use do/does/did with have to in questions and negative sentences
     • We use make or supossed to when we talk about an obligation (or an expectation) in the present from another person
   • Necessity
     • We use must to talk about rules and laws in the present and future
     • We use need to talk about necessity in the past, present, or future
     • We use don’t need to/ needn’t or don’t have to when there is no obligation or necessity
   • Prohibition
     • We use must not (mustn’t) to talk about something that is prohibited, against the law, or breaking rules

3. Verbs of permission

   • We use can, be allowed to, and let to ask for and give permission, or to say that something is permitted
   • We use can’t, isn’t/aren’t allowed to, or don’t/doesn’t let whe we want to talk about lack of permission

4. Using adverbs

   • Frequency: We use frequency adverbs tos ay how often things happen. They usually go before the verb in a sentence, but after the verb be. They don’t normally end in -ly
   • Manner: We use adverbs of manner tos ay how someone does something, They usually go at the end of a sentence. We usually add -ly to an adjective or a noun to forma n adverb of manner
   • Opinion and attitude: We use opinión and attitude adeverbs to express our opinión and to show how we feel. They usually go at the start of a sentence and we use a comma after them
   • Degree: We use adverbs of degree to describe the intesity of something. We usually use them before adjectives, verbs, or other adverbs
   • Spelling: We form a lot of adverbs by adding -ly to an adjective and there are sometimes spelling changes before you add -ly if an adjective ends in: y, -le, -ic

5. Modals of speculation, deduction, and obligation in the past

   • Speculation: We use may have, might have, and could have + past participle to talk about past possibility
   • Deduction: We use must have + past participle to show that we are certain that something happened in the past and we use can’t/ couldn’t have + past participle to show that something was not posible in the past
   • Opinion: We use should(n’t) have + past participle to give a negative opinion about a past action that you can’t change
   • Obligation: We use didn’t need to + infinitive without to to show a lack of necessity / obligation in the past and we use was/ were supposed to + infinitive without to to show you were expected to do something, but didn’t