lunes, 21 de enero de 2013

Can

Can is an auxiliary verb, a modal auxiliary verb. We use can to:

talk about possibility and ability
make requests
ask for or give permission

Structure of Can

subject + can + main verb
The main verb is always the bare infinitive (infinitive without "to").

	subject	auxiliary verb	main verb
+	I	can	play	tennis.
-	He	cannot	play	tennis.
-	He	can't	play	tennis.
?	Can	you	play	tennis?

Notice that:

Can is invariable. There is only one form of can.
The main verb is always the bare infinitive.

The main verb is always the bare infinitive (infinitive without "to"). We cannot say:

Use of Can

can: Possibility and Ability

We use can to talk about what is possible, what we are able or free to do:

She can drive a car.
John can speak Spanish.
I cannot hear you. (I can't hear you.)
Can you hear me?

Normally, we use can for the present. But it is possible to use can when we make present decisions about future ability.

Can you help me with my homework? (present)
Sorry. I'm busy today. But I can help you tomorrow. (future)

CAN for Present Ability Games

can: Requests and Orders

We often use can in a question to ask somebody to do something. This is not a real question - we do not really want to know if the person is able to do something, we want them to do it! The use of can in this way is informal (mainly between friends and family):

Can you make a cup of coffee, please.
Can you put the TV on.
Can you come here a minute.
Can you be quiet!

can: Permission

We sometimes use can to ask or give permission for something:

Can I smoke in this room?
You can't smoke here, but you can smoke in the garden.

(Note that we also use could, may, might for permission. The use of can for permission is informal.)

Could

Could is an auxiliary verb, a modal auxiliary verb. We use could to:

talk about past possibility or ability
make requests

Structure of Could

subject + could + main verb

The main verb is always the bare infinitive (infinitive without "to").

	subject	auxiliary verb	main verb
+	My grandmother	could	swim.
-	She	could not	walk.
-	She	couldn't	walk.
?	Could	your grandmother	swim?

Notice that:

Could is invariable. There is only one form of could.
The main verb is always the bare infinitive.

The main verb is always the bare infinitive. We cannot say:

Use of Could

could: Past Possibility or Ability

We use could to talk about what was possible in the past, what we were able or free to do:

I could swim when I was 5 years old.
My grandmother could speak seven languages.
When we arrived home, we could not open the door. (...couldn't open the door.)
Could you understand what he was saying?

We use could (positive) and couldn't (negative) for general ability in the past. But when we talk about one special occasion in the past, we use be able to (positive) and couldn't (negative). Look at these examples:

	Past
	General	Specific Occasion
+	My grandmother could speak Spanish.	A man fell into the river yesterday. The police were able to save him.
-	My grandmother couldn't speak Spanish.	A man fell into the river yesterday. The police couldn't save him.

COULD for Past Ability Games

could: Requests

We often use could in a question to ask somebody to do something. The use of could in this way is fairly polite (formal):

Could you tell me where the bank is, please?
Could you send me a catalogue, please?

Past simple

Was/were

Present simple & present continuos.

Present simple Advers of frequency

GERUND & NOUN

Both gerunds and infinitives can be nouns, which means they can do just about anything that a noun can do. Although they name things, like other nouns, they normally name activities rather than people or objects. Here are five noun-uses of gerunds and infinitives (and one additional non-noun use, the adjective complement, that we throw in here, free of charge).

Gerunds and infintives can both function as the subject of a sentence:

Playing basketball takes up too much of her time.
To play basketball for UConn is her favorite fantasy.

It is not impossible for an infinitive to appear at the beginning of a sentence as the subject (as in Ib), but it is more common for an infinitive to appear as a Subject Complement:

Her favorite fantasy is to play basketball for UConn. The gerund can also play this role:
Her favorite fantasy is playing basketball for UConn.

Both of these verbal forms can further identify a noun when they play the role of Noun Complement and Appositive:

Her desire to play basketball for UConn became an obsession.
I could never understand her desire to play basketball for UConn.
Her one burning desire in life, playing basketball for UConn, seemed a goal within reach.

The infinitive is often a complement used to help define an abstract noun. Here is a very partial list of abstract nouns, enough to suggest their nature. Try following these adjectives with an infinitive phrase (their desire to play in the championship game, a motivation to pass all their courses, her permission to stay up late, a gentle reminder to do your work) to see how the phrase modifies and focuses the noun.

advice
appeal
command
decision
desire
fact
instruction
motivation opportunity
order
permission
plan
possibility
preparation
proposal
recommendation refusal
reminder
request
requirement
suggestion
tendency
wish

Infinitive phrases often follow certain adjectives. When this happens, the infinitive is said to play the role of Adjective Complement. (This is not a noun function, but we will include it here nonetheless.)

She was hesitant to tell the coach of her plan.
She was reluctant to tell her parents, also.
But she would not have been content to play high school ball forever.

Here is a list of adjectives that you will often find in such constructions.

ahead
amazed
anxious
apt
ashamed
bound
careful
certain
content
delighted determined
disappointed
eager
eligible
fortunate
glad
happy
hesitant
liable
likely lucky
pleased
proud
ready
reluctant
sad
shocked
sorry
surprised
upset

Although we do not find many infinitives in this next category, it is not uncommon to find gerunds taking on the role of Object of a Preposition:

She wrote a newspaper article about dealing with college recruiters.
She thanked her coach for helping her to deal with the pressure.

Two prepositions, except and but, will sometimes take an infinitive.

The committee had no choice except to elect Frogbellow chairperson.
What is left for us but to pack up our belongings and leave?

And, finally, both gerunds and infinitives can act as a Direct Object:

Here, however, all kinds of decisions have to be made, and some of these decisions will seem quite arbitrary. The next section is about making the choice between gerund and infinitive forms as direct object.

Verbs that take other verb forms as objects are called catenatives (from a word that means to link, as in a chain). Catenatives can be found at the head of a series of linked constructions, as in "We agreed to try to decide to stop eating between meals." Catenatives are also characterized by their tendency to describe mental processes and resolutions. (Kolln)

Although it is seldom a serious problem for native English speakers, deciding whether to use a gerund or an infinitive after a verb can be perplexing among students for whom English is a second language. Why do we decide to run, but we would never decide running? On the other hand, we might avoid running, but we would not avoid to run. And finally, we might like running and would also like to run. It is clear that some verbs take gerunds, some verbs take infinitives, and some verbs take either. The following tables of verbs should help you understand the various options that regulate our choice of infinitive or gerund.

Parts of speech SONG

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Here's a little rhyme — by David B. Tower & Benjamin F. Tweed —that teachers used in days gone by to help students learn the parts of speech. (We include it here in response to popular demand. Why the song leaves out pronouns is a mystery. A writer from Richland, Washington, suggests "A PRONOUN replaces any noun: / he, she, it, and you are found. ) It has been set to music, but we'll leave that up to you to discover or create for yourself:

Three little words you often see
Are ARTICLES: a, an, and the.

A NOUN's the name of anything,
As: school or garden, toy, or swing.

ADJECTIVES tell the kind of noun,
As: great, small, pretty, white, or brown.

VERBS tell of something being done:
To read, write, count, sing, jump, or run.

How things are done the ADVERBS tell,
As: slowly, quickly, badly, well.

CONJUNCTIONS join the words together,
As: men and women, wind or weather.

The PREPOSITION stands before
A noun as: in or through a door.

The INTERJECTION shows surprise
As: Oh, how pretty! Ah! how wise!

The whole are called the PARTS of SPEECH,
Which reading, writing, speaking teach.