Four sources for audio and video streams

Here you can have access to the NPR of the NYC region.  It could be useful if you want to improve your listening comprehension of American English.  You can listen to the live FM broadcast or go their show archives.  I personally like Radiolab, Selected Shorts and Fresh Air among the shows they air.

Here you can have access to the BBC website, which also airs on the WNYC in the mornings Brussels time.  It could be useful to improve your listening comprehension of British English.  They also have links under "Learning English", where you can find numerous tools for learners of English as a second language.

Here you can have access to the audio and video streams on The Economist website.  This again is a good source for improving British English listening comprehension. I recommend using "The Week Ahead", which is released after 5:00PM every Friday.

Here you can have access to TED, which is a good source for numerous talks on a very wide range of topics.  Most talks are given by Americans and Canadians, but there are also other speakers of different nationalities, including some British.

Prepositions

Basic prepositions: Here you can find some exercises on basic prepositions.  The key to the exercises is hereby made available. (Source: English Grammar in Use: Intermediate by Raymond Murphy)

Noun, adjective and verb + preposition:
Here you can find some exercises on nouns, adjectives and verbs which are used with certain prepositions.  The key for the exercises are also hereby made available. (Source: English Grammar in Use: Intermediate by Raymond Murphy). Here is a list of words with prepositions.

Phrasal verbs:
Here you can find some exercises on phrasal verbs.  The key to the exercises is hereby made available. (Source: English Grammar in Use: Intermediate by Raymond Murphy)

You can hereby find a link for more online exercises on the topics above.

Tenses and key words

Here you can find many exercises on tenses.  I am also hereby making a list of all the tenses and key words available.

Countable and uncountable nouns and quantifiers

Here is a document with information and exercises on countable and uncountable nouns; the key to the exercises in hereby made available.
Here is another document with information and exercises on countable and uncountable nouns.

What and which

Here you can find a document with information on the use of 'what' and 'which'.

Plans

Here are the four different functions we can use to talk about plans:
1. I will/shall call you in 10 minutes. (spontaneous)
2. I am going to spend the evening at home. (premeditated in spoken English)
    I will/shall be spending the evening at home. (premeditated in written English with an action verb)
    I will be in New York during Easter.  (premeditated in written English with a state verb)
3. I am flying to New York at 8:00AM tomorrow. (premeditated and arranged with an action verb)
    I am in New York during Easter. (premeditated and arranged with a state verb)
4. My Flight departs at 8:00AM tomorrow. (time-tabled event) 
 
Here are some links to some exercises on this topic: 
 
  http://www.englishgrammarsecrets.com/goingtoorwill/menu.php
  http://www.englishgrammarsecrets.com/presentformsforfuture/menu.php
  http://www.englishgrammarsecrets.com/willbedoing/menu.php

State vs. action verbs

Here is  a document where you can find information and exercises on state vs. action verbs, along with key for the  exercises. (Source: English Grammar in Use: Intermediate by Raymond Murphy)

Here is a link for a webpage where you can find some  exercises on the same topic.   

Here you can find the list of verbs we have looked at. (Source: LONGMAN Advanced Learners’ Grammar by Mark Foley &  Diane Hall)

Position of adverbs

Here are the main rules and exceptions on the position of adverbs in sentences:

First rule: if there is only one verb in the sentence, the adverb comes before the verb as in the following example: He usually comes to work on time.
Exception to the first rule: if the only verb in the sentence is 'to be', the adverb comes after the verb as in the following example:  He is usually on time.

Second rule: If there is more than one verb in the sentence, the adverb comes after the first verb as in the following example: He has already arrived at work.
First exception to the second rule: if the first verb in the sentence is an auxiliary verb with 'to', i.e., have to, need to, ought to and used to, the adverb comes before the first verb as in the following example: He usually has to start working by 9:30 AM.
Second exception to the second rule: if the first verb in the sentence is a contracted negation, the adverbs 'probably', 'possibly' and 'certainly' come before the first verb as in the following example: He probably won't come to work on time.

These being the main rules and exceptions, there is more to this topic.  You can find more information on this webpage, which also provides you with some exercises. 

Here is another document with exercises on the same topic.  You can find the key for the exercises here.

'Like' vs. 'as'

Here you can find the document and exercises on the use of 'like and 'as' along with the key.

Greetings and closers

Here is a list of greetings you can use in your formal emails depending on the recipient:

• Anonymous singular:

1. Dear Sir/Madam
2. Dear Madam/Sir
3. Dear Sir or Madam
4. Dear Madam or Sir

• Anonymous plural:

1. Dear Sirs/Ladies
2. Dear Ladies/Sirs
3. Dear Sirs and/or Ladies
4. Dear Ladies and/or Sirs

• With a given male name: Dear Mr Smith

• With a given female name:

1.  Dear Ms Smith (civil status irrelevant or unknown)
2.  Dear Mrs Smith (married)
3.  Dear Miss Smith (single and younger than fifty)

• With given names to a group of less than three people (male):  Dear Messrs Smith and Jones

• With given names to a group of less than three people (female):

1. Dear Mses Smith and Jones (civil statuses unknown, irrelevant or different)
2. Dear Mesdames Smith and Jones (both of them married)
3. Dear Misses Smith and Jones (both of them single and younger than fifty)

• With given names to a group of less than three people (mixed gender and not related to each other by marriage or blood): 

1. Dear Messrs Smith and Jones, and Ms Presley 
2. Dear Ms Presley, and Messrs Smith and Jones

• With a given name to a couple who use the same last name:

1. Dear Mr and Mrs Smith 
2. Dear Mrs and Mr Smith 

• With given names to a group of more than three people (mixed gender):

1. Dear Sirs/Ladies
2. Dear Ladies/Sirs
3. Dear Sirs and Ladies
4. Dear Ladies and Sirs

• With given names to a group of more than three people (all male): Dear Sirs

• With given names to a group of more than three people (all female): Dear Ladies 

• With a given first and last name and the gender is not clear:  Dear Alex Smith

Here is a list of closers which apply to all formal emails regardless of their content:

• With kind regards
• Kind regards
• Regards

You can hereby find a document on how to address various VIPs in different contexts.