There are a number of ways to add emphasis to your sentences in English. Use these forms to emphasize your statements when you are expressing your opinions, disagreeing, making strong suggestions, expressing annoyance, etc.

1. Use of the Passive
The passive voice is used when focusing on the person or thing affected by an action. Generally, more emphasis is given to the beginning of a sentence. By using a passive sentence, we emphasize by showing what happens to something rather than who or what does something.
Example: Reports are expected by the end of the week.
In this example, attention is called to what is expected of students (reports).

2. Inversion
Invert the word order by placing a prepositional phrase or other expression (at no time, suddenly into, little, seldom, never, etc.) at the beginning of the sentence followed by inverted word order.
Examples: At no time did I say you couldn't come.
Hardly had I arrived when he started complaining.
Little did I understand what was happening.
Seldom have I felt so alone.
Note that the auxiliary verb is placed before the subject which is followed by the main verb.

3. Expressing Annoyance
Use the continuous form modified by 'always', 'forever', etc.
to express annoyance at another person's action. This form is considered an exception as it used to express a routine rather than an action occurring at a particular moment in time.
Examples:
Martha is always getting into trouble.
Peter is forever asking tricky questions.
George was always being reprimanded by his teachers.
Note that this form is generally used with the present or past continuous (he is always doing, they were always doing).

4. Cleft Sentences: It
Sentences introduced by 'It is' or 'It was' are often used to emphasize a specific subject or object. The introductory clause is then followed by a relative pronoun.
Examples:
It was I who received the promotion.
It is the awful weather that drives him crazy.

5. Cleft Sentences: What
Sentences introduced by a clause beginning with 'What' are also used to emphasize a specific subject or object. The clause introduced by 'What' is employed as the subject of the sentence as is followed by the verb 'to be'.
Examples:
What we need is a good long shower.
What he thinks isn't necessarily true.

6. Exceptional Use of 'Do' or 'Did'
You have probably learned that the auxiliary verbs 'do' and 'did' are not used in positive sentences - for example: He went to the store. NOT He did go to the store. However, in order to emphasize something we feel strongly these auxiliary verbs can be used as an exception to the rule.
Examples:
No that's not true. John did speak to Mary.
I do believe that you should think twice about this situation.
Note this form is often used to express something contrary to what another person believes.