CONDITIONAL SENTENCES

There are three types of conditionals or  if-clauses.

type	condition
I	condition possible to fulfill
II	condition in theory possible to fulfill
III	condition not possible to fulfill (too late)

Form

type	if clause	main clause
I	Simple Present	will-future (or Modal + infinitive)
II	Simple Past	would + infinitive *
III	Past Perfect	would + have + past participle *

Examples (if-clause at the beginning)

type	if clause	main clause
I	If I study,	I will pass the exam.
II	If I studied,	I would pass the exam.
III	If I had studied,	I would have passed the exam.

Examples (if-clause at the end)

type	main clause	if-clause
I	I will pass the exam	if I study.
II	I would pass the exam	if I studied.
III	I would have passed the exam	if I had studied.

Examples (affirmative and negative sentences)

type		Examples
		long forms	short/contracted forms
I	+	If I study, I will pass the exam.	If I study, I'll pass the exam.
	-	If I study, I will not fail the exam. If I do not study, I will fail the exam.	If I study, I won't fail the exam. If I don't study, I'll fail the exam.
II	+	If I studied, I would pass the exam.	If I studied, I'd pass the exam.
	-	If I studied, I would not fail the exam. If I did not study, I would fail the exam.	If I studied, I wouldn't fail the exam. If I didn't study, I'd fail the exam.
III	+	If I had studied, I would have passed the exam.	If I'd studied, I'd have passed the exam.
	-	If I had studied, I would not have failed the exam. If I had not studied, I would have failed the exam.	If I'd studied, I wouldn't have failed the exam. If I hadn't studied, I'd have failed the exam.

* We can substitute could or might for would (should, may or must are sometimes possible, too).

I would pass the exam.

I could pass the exam.

I might pass the exam.

I may pass the exam.

I should pass the exam.

I must pass the exam.

VERB PATTERNS

   VERB + TO INFINITIVE

decide          hope          learn          offer          manage          choose promise         plan           pretend     want          seem             expect *help             *need        *start         agree         afford            refuse would like/hate/love

·         Help can also be followed by infinitive without to:

He helped me (to) move the armchair

·         Can’t help + -ing  has a different meaning:

I couldn’t help laughing when I saw him fall down (no pude evitar reirme)

·         In British English need can be an auxiliary and then it is followed by infinitive without to:

We needn’t reserve seats although We don’t need to reserve seats would be more usual.

·         Need + ing has a passive meaning:

Your hair is too long. It needs cutting (= to be cut)

·         Start can be followed by to infinitive or –ing without difference in meaning:

It started to rain / It started raining

  VERB + ING

enjoy            finish           go on                   spend (time)          suggest mind             avoid           can’t stand          fancy (apetecer)     miss                              *like      *love           *hate           *prefer

Like, love, hate, prefer can also be followed by to infinitive. In British English the -ing  is preferred when we talk about enjoyment  and the infinitive when we talk about choices or habits.

I like climbing mountains

When I serve tea, I like to pour the milk first

In American English the to infinitive is commom in both senses. They would say I like to climb mountains

  VERB + TO INFINITIVE / ING WITH CHANGE OF MEANING

forget               remember                try                stop

·         You forget / remember doing things after they happened

I remember visiting London when I was 15

I’ll never forget going to my first live concert last summer

·         You forget / remember to do things before you do them

Remember to buy bread on your way home

He forgot to switch off the lights before leaving

·         Try to do means attempt to (intentar). You make an effort to do something

I tried to lift the box but I couldn’t, it was too heavy.

·         Try doing means experiment to see what will happen (probar)

If you don’t like the soup, try adding some pepper

·         Stop doing means the action finishes. He stopped running (he didn’t run any more)

·         Stop to do expresses purpose (in order to do)  He stopped to rest (in order to rest)

MAKE and LET

These two verbs are followed by object and infinitive without to:

That film makes me feel good

She didn’t let us use dictionaries in the exam

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