Verbs followed by preposition + gerund

These verbs can be followed by for + gerund:
apologize, blame, arrest, praise, forgive, punish, tell off, thank
Have you apologized to Sam for breaking her pen?

These verbs can be followed by from + gerund:
stop, prevent, discourage
His parents prevented him from leaving the town.

Congratulate and insist are followed by on + gerund.
She insisted on paying for the drink.

Warn can be followed by against + gerund.
We tried to warn her against driving in the snow.
Warn can also be used with of or about + noun.
Posters have been put up warning people of the dangers of smoking.

Verb+Preposition

Many verbs are followed by a preposition:
hear of: Have you heard of Spice Girls?
read about: I read about the fight between the two families.
speak to: Camila won't speak to Daniel.

Most verbs can have more than one preposition. Usually this changes the meaning:
apologise for: I apologise for my behaviour last night.
apologise to: I apologised to John for swearing at his sister.
complain about: Leigh complained about the food.
complain to: Leigh complained to the waiter.

Sometimes using a different preposition after a verb doesn't change the meaning:
speak to/with: I need to speak to/with you.
think about/of: I'm thinking of/about you.

Sometimes using the same preposition after a verb can have more than one meaning:
She went through the park. (go through = go cross)
She went through the details (go through = to explain)

Afterwards / Beforehand

After: Después de... http://www.wordreference.com/es/translation.asp?tranword=after
Afterwards: Después de esto http://www.wordreference.com/es/translation.asp?tranword=afterwards

Before: Antes de... http://www.wordreference.com/es/translation.asp?tranword=before
Beforehand: Antes de esto http://www.wordreference.com/es/translation.asp?tranword=beforehand

Rules:

1- After & Before: are followed by a noun or verb.
2- Afterwards & Beforehand: replaces a noun or verb.
3- Earlier & Later: refer to time.
4- Before & After: refer to events.
5- After: después de
6- Afterwards: después de esto
7- Before: antes de
8- Beforehand: antes de esto

I went there and afterwards I went straight back home.
After I went there I went straight back home.

Before I came here I had had lunch on the tube.
I came here at 15:45, beforehand I had had lunch on the tube.
!!!! Beforehand with Past Perfect

Contrasting ideas

But contrasts two ideas in the same sentence.
http://www.wordreference.com/es/translation.asp?tranword=but
The weather was bad but she enjoyed the trip.

Although and though (informal) are also used to contrast ideas in the same sentence. They can go at the beginning of a sentence or in the middle.
http://www.wordreference.com/es/translation.asp?tranword=although
http://www.wordreference.com/es/translation.asp?tranword=though
Although the weather was bad, she enjoyed the trip.

However contrasts ideas in two different sentences. It often comes at the beginning of the second sentence and is followed by a comma.
http://www.wordreference.com/es/translation.asp?tranword=however
The weather was bad. However, she enjoyed the trip.

Nevertheless is a more formal alternative to however.
http://www.wordreference.com/es/translation.asp?tranword=nevertheless
The English aren't normally very emotional people. Nevertheless, they get very excited at sporting events.

In spite of and despite are both followed by a gerund or a noun. They can go at the beginning of the sentence or in the middle.
http://www.wordreference.com/es/translation.asp?tranword=in%20spite%20of
http://www.wordreference.com/es/translation.asp?tranword=despite
Despite the fact that the weather was bad, she enjoyed the trip.
If the subject of the verbs in the two clauses is the same, the gerund can be used immediately after despite or in spite of without a preceding noun/pronoun.
She played tennis despite feeling ill.

Whereas and while are used to contrast two ideas in the same sentence.
http://www.wordreference.com/es/translation.asp?tranword=whereas
http://www.wordreference.com/es/translation.asp?tranword=while
The first photo shows a child having fun whereas/while the second one shows a rather sad man on his own.

Relative clauses

Relative clauses give extra information about something or someone in the main clause.


Defining relative clauses

Defining relative clauses contain information which is essential for our understanding of the whole sentence.
The woman who normally comes to clean our windows is on holiday this month.
In each case, the relative clause identifies which person or thing is being talked about.

Features of defining relative clauses.
- No comas are required either at the beginning or the end of the relative clause.
- That can be used instead of who for people and which for things, particulary in spoken English.

	For people	For things
Subject	who/that	which/that
Object	who/that/whom	which/that
Possessive	whose	whose

*whom is more formal than who

- The relative pronoun can be omitted if it is the object of the verb in the relative clause.
I'm enjoying the book (which/that) you lent me.
- The realtive pronoun cannot be omitted if it is the subject of the verb in the relative clause.
That's the shop assistant who/that served me the last time I came here.


Non-defining relative clauses.

Non-defining relative clauses contain information which is not essential for our understanding of the sentence. We can identify which person or thing is being talked about without the information in the relative clause.
Their new palace, which has five bedrooms and a games room, is much larger than their previous one.

Features of non-defining relative clauses
- Commas are required both at the beginning and the end of the relative clause (except when the end of the relative clause is also the end of the sentence).
- That cannot be used in place of who or which.

	For people	For things
Subject	who	which
Object	who/whom	which
Possessive	whose	whose

- Relative pronouns cannot be omitted from non-defining relative clauses.
Her english teacher, who/whom everyone in the class adored, announced that he was leaving the school.
- Non-defining relative clauses are more common in written English.
- Which can be used in non-defining relative clauses to refer to a whole clause.
No one phoned him on his birthday, which made him feel rather depressed.


Relative clauses and prepositions

Prepositions usually come at the end of defining and non-defining relative clauses.
In defining relative clauses the relative pronoun is usually omitted.
The town I grew up in has changed a lot since I left.
In non-defining relative clauses the relative pronoun is never omitted.
Mark Ralf, who I used to work with, lives in Berlin now.

In more formal English, prepositions often come before the relative pronouns whom for people and which for things (in which case the pornoun cannot be omitted).
The head waiter, to whom we addressed our complaint, was not particularly helpful.


Relative adverbs: where, when and why.

Where, when and why can be used in relative clauses after nouns which refer to a place, a time or a reason.

Where has the meaning "in/at which"
Defining: They've booked a week in that campsite where we stayed last year.
Non-defining: He's in Southlands Hospital, where you were born.

When has the meaning "on/in which" and can be omitted in defining relative clauses.
Defining: Do you remember that day (when) we went to Berlin and it snowed?
Non-defining: I'm going on holiday in October; when most people are back at work.

Why has the meaning "for which" and can be omitted in defining relative clauses.
Defining: The reason (why) I'm phoning is to ask you for Anne's address.

Present Perfect or Past Simple (2)?

Use the Present Perfect + how long?, for, and since to talk about a period of time from the past until now.
How long have you been married? I've been married for 10 years. (= I'm married now)

Use the Past Simple + how long? and for to talk about a finished period of time in the past.
How long was the married? He was married for two years. (=He's not married now)

!!!!
Don't use since with the Past Simple. He was Prime Minister since 1998.
You have to use from... to. He was Prime Minister from 1999 to 2003.

Present Perfect + for & since

Use the present perfect + for(durante) & since(desde) to talk about actions and states wich started in the past and are still true now.

Where do you live now? In London.
How long have you lived there? I've lived there since 1990.

Where do you study? I study in the University.
How long have you studied there? I've studied there for three yers.

Use How long? to ask the questions about the duration of an action or a state.

Use SINCE with the beginning of a period of time.
Use FOR + a period of time.

!!!!!
You dan't use Present Simple here. How long do you live here? I live in London since 1980.