Emphatic Use of Do, Does, and Did

6. Emphatic statements 
In spoken English, words can be emphasized by being pronounced with a heavier stress than usual. This type of emphasis is usually indicated in written English by means of italics or underlining. In the following examples, emphasized words are indicated by means of underlining.

Emphatic statements are often used in conversation; for instance, when one speaker is contradicting another.
e.g. "I don't believe he works very hard."
      "Yes, he does work hard."

When it is desired to emphasize a verb, it is generally the first auxiliary which is stressed. For instance, in the sentence I am working hard, the verb can be emphasized by stressing the auxiliary am.
e.g. I am working hard.

Usually, no auxiliary is required for affirmative statements in the Simple Present and Simple Past. However, in order to make such statements emphatic, for verbs other than the verb to be, the auxiliary to do is used, followed by the bare infinitive. For example, in the Simple Present, the emphatic form of the verb to work is formed with the Simple Present of the auxiliary to do, as shown below:

Affirmative Statement	Emphatic Affirmative Statement
I work.	I do work.
You work.	You do work.
He works.	He does work.
She works.	She does work.
It works.	It does work.
We work.	We do work.
They work.	They do work.

In the Simple Past, the emphatic form of the verb to work is formed with the Simple Past of the auxiliary to do, as shown below:

Affirmative Statement	Emphatic Affirmative Statement
I worked.	I did work.
You worked.	You did work.
He worked.	He did work.
She worked.	She did work.
It worked.	It did work.
We worked.	We did work.
They worked.	They did work.

For the emphatic form of the Simple Present of the verb to be, no auxiliary is used. Instead, the verb itself is stressed. For example:

Affirmative Statement	Emphatic Affirmative Statement
I am ready.	I am ready.
It is ready.	It is ready.
They are ready.	They are ready.

Similarly, for the emphatic form of the Simple Past of the verb to be, no auxiliary is used. Instead, the verb itself is stressed. For example:

Affirmative Statement	Emphatic Affirmative Statement
I was ready.	I was ready.
It was ready.	It was ready.
They were ready.	They were ready.

Examples of emphatic statements in all of the present and past tenses are given in the following table:

Tense	Affirmative Statement	Emphatic Statement
Simple Present	I work.	I do work.
Present Continuous	I am working.	I am working.
Present Perfect	I have worked.	I have worked.
Present Perfect Continuous	I have been working.	I have been working.
Simple Past	I worked.	I did work.
Past Continuous	I was working.	I was working.
Past Perfect	I had worked.	I had worked.
Past Perfect Continuous	I had been working.	I had been working.
Simple Present of to be	I am ready.	I am ready.
Simple Past of to be	I was ready.	I was ready.

It should be noted that questions may be emphasized in the same way as statements.
e.g. Did it work?
      Are they ready?

Sometimes it is desired to emphasize a negative statement containing the word not. In spoken English, often both the auxiliary and the word not are stressed, but in written English, usually only the word not is underlined or written in italics. For example:

Negative Statement	Emphatic Negative Statement
He does not know the answer.	He does not know the answer.

When a contracted form of the word not is used, it is generally the auxiliary which is stressed in an emphatic statement. For example:

Negative Statement	Emphatic Negative Statement
He doesn't know the answer.	He doesn't know the answer.