Do I have to or Have I to do: What's the Difference?

When you begin to learn the English language, the first verb tenses that you study are the present simple tense. The rules are not that complicated:

We use do/does or is/are as question words when we want to ask yes/no questions.
We use does and is with third person singular pronouns (he, she, it) and with singular noun forms.
We use do and are with other personal pronouns (you, we they) and with plural noun forms.

Auxiliary verbs (also known as ’helping verbs’) include be, do and have. They are used along with the main verb in a sentence to make questions, negative statements, passives and tenses.
In this question, “Do you like Asian food?” – do is the auxiliary verb, like is the main verb.
In questions, auxiliary verbs come before the subject – in our example question, you is the subject.
You should only stop and practice the present simple in all forms (reading, writing, speaking and listening) and all basic auxiliaries before you move on with other grammar rules.
Now, if you want to ask someone:

Do I have to do this task now?
Have I to do this task now?

Both of them are correct, but:

is more common.
is old-fashioned and never used.

The most correct and more frequently used is ‘Do I have to do’ this task now?
Let’s see why.
The most important question to ask yourself whenever you wish to express your thoughts in English is this:
When asking a question with a yes or no response for a future action, the usual tense is in the present.
Now, let’s only focus on the Present Simple and why we should say ‘Do I have to do…?’.
The Present Simple is used to describe events, states, general actions that recur. In general, we say that we use it for routine actions or permanent states. (I love chocolate).
Example:

Affirmative: I drive to work every day.
Negative: I don’t drive to work every day.
Question: Do you drive to work every day?

In English, it’s important to define the sentence structure, so that we all understand what the auxiliary and the main verb are. Also, a question, a sentence or phrase that shows that the speaker wants the listener to give them some information, to complete a task or in some other way satisfy the request, is in the inverted format of verb-subject, not the usual subject-verb format

What’s an auxiliary verb?

As we’ve mentioned, an auxiliary is verb is important to give more meaning to a verb – it’s a helping verb! It gives more meaning so that other people understand clearly what we desire to say. In this sample, we have use ‘do’ and ‘does’ in negative and question forms.
Example:

You don’t swim very often.
Do you swim often?
He/She doesn’t go to the gym on Saturday.
Does he/she go to the gym on Saturday?

There are other auxiliaries used in English, like the modal auxiliaries (can, must, should, could and have to).
As we saw in the example above, for every question in the present simple you should use the auxiliary ‘do’ or ‘does’ at the beginning of a question.
Example:

Do I have to do this task now?

What’s the main verb?
The main verb is the most important one in a sentence. Without the main verb, other people might not understand what we want to say.
If you omit drive in this sentence:

She doesn’t **** to work every day.

You can see that something is missing. Let’s analyze our question and see what the main verb is.
[Do] I have to do this task now?
Do is the main verb in this sentence. It’s used both as an auxiliary and main verb in this case.

Have To and Has To

As I mentioned before, ‘have to’ is considered by some an auxiliary verb. Its place is always after the subject. In the case, of a question, after another auxiliary verb. In the present tense, affirmative form, you need to be careful as it changes with the third person singular.
Question form example:

Do you have to get up early?
Does she have to drive to work every day?
Does he have to wake up every morning at 8 o’clock to go to work.
Do they have to leave the pets behind?

Notice that in forming the questions, we only use the auxiliary verb “have to”.
Example:

Yesterday I had to get up early.
She has to drive to work every day.
He has to wake up every morning at 8 o’clock to go to work.
They have to leave the pets behind.

So, our question is correctly stated: Do I have to do this task now?
Question form examples:

Do I have to do my laundry on weekends?
Does she have to feed the dogs every morning?

Notice how in the affirmative sentence with the third person singular ‘she’ we use ‘has to’ and in the question format, we use ‘have to’.
For questions and negatives, we use ‘do’ and ‘does’ for the present and ‘did’ for the past.
The structure of the negative looks like this:

What are modal verbs?

We’ll start with two common modal verbs: “must” and “have to. Must means that the obligation to do something comes from the speaker. In other words, it’s not a rule. Have to implies that the obligation comes from someone else; it’s something the speaker can’t change. Additionally, must expresses the speaker’s feelings, whereas have to expresses, above all, an impersonal idea.”
Example:

This cake is delicious. You must try it!

This cake is delicious. You have to try it!

When you are not giving your personal opinion, you need to use ‘have to’, not ‘must’.
Example:

Suzy doesn’t have a dishwasher at home. She has to do her dishes. (it’s a fact, not a personal opinion)
Suzy doesn’t have a dishwasher at home but she doesn’t want to do her dishes. I told her she must do it! (this is a personal opinion)

‘Must’ is also used in written rules and instructions.
Example:

You must fasten your seatbelt when you are in the car.
The assignment must be submitted by the 23rd of September.

The other difference is that ‘must’ can only be used in the present. If we need to express an obligation in the past, then we require to use ‘have to’ in the past, which is ‘had to’.
Example:

Yesterday morning I missed the bus. I had to walk to school.
Kylie was sick yesterday. She had to go to the doctor.

Notice how we still use ‘had to’ in the past for third person singular.

Some rules on the use of ‘have to’

Have to in negatives sentences expresses the idea that “you are not obligated to do something, but you can do it if you want to” and requires an auxiliary verb: You don’t have to pay for this.
Also, the word must expresses submission to various general laws; that is, something needs to be done, because it is accepted as proper in society.
Have to expresses submission to private “laws,” that is, you are following your conscience, moral principles, or duties.

Practice using the auxiliary verbs and modal verbs properly and in no time at all, you’ll be conversing like a native English speaker.

Clap