Obligations

Positive obligations for the present, future or in general:

Stronger:
You have to put on your seat belt. (US)
We are going to/will have to go through the customs when we arrive in New york. (future)
She must put on her seat belt. (UK)
Members shall follow the club rules. (formal/legal/religious/moral codes in writing)

Weaker:
You should take off your shoes in their house.
You ought to take off your shoes in their house. (UK)

Negative obligations for the present, future or in general:
Stronger:
You cannot drive without your seat belt on. (US)
You must not drive without your set-belt on. (UK)
Thou shall not kill. (formal/legal/religious/moral codes in writing)

Weaker:
You should not enter their house with your shoes on.
You ought not to enter their house with your shoes on. (UK)

Positive obligations for the past:

Stronger:
We had to go through the customs when we came from the US to Belgium last week.

Weaker:
You should have taken off your shoes when you entered their house yesterday evening.
You ought to have taken off your shoes when you entered their house yesterday evening. (UK)

Negative obligations for the past:

Stronger: 
The waiter could not serve beer to my 17-year old cousin when we were in the US last year.  (US)

Weaker:
You should not have entered their house with your shoes on yesterday evening.
You ought not to have entered their house with your shoes on yesterday evening. (UK)

Lack of obligations for the present, future or in general:

You do not have to take off your shoes when you go through the security check at the airports in Europe.
You are not going to/will not have to take off your shoes at the security check in Zaventem airport when you arrive there. (future)

Lack of obligations for the present, future or in general:

We did not have to take off your shoes when we went through the security check at the airport last week.

I am hereby making some exercises on have to vs. must and should along with the key available.

Composite nouns and possessives

Here you can find some information on composite nouns and possessives with exercises, as well as the key for the exercises. I am hereby also making another document on the same topics with exercises, as well as the key for the exercises.

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

Wishes

Here you can find some information and exercises on wishes along with the key.
Here you can find more examples and an exercise with the key on wishes.

'Like' vs. 'as'

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

All and whole

Here you can find some information with some exercises on 'all' and 'whole'.  Here is the key for the exercises.

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.

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.

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)