Difference Between Did and Had

Verbs are an indispensable part of sentences and communication of everyday use. Did and had are two such irregular verbs that perform the function of indicating a course of action.

While the two may appear to mean the same, they have considerable differences. 

Did vs Had

The difference between did and had is that did is used to indicate a task that has already been completed. For example, Ryan did his homework well on time.

On the other hand, had has been used to indicate the possession of a thing in the past. For instance, Robert had owned a macbook for the last twelve years before he switched to Windows. 

By definition, did refers to a state of action that is complete. The verb did have use in sentences containing first persons, second persons, and third persons.

Examples include Riya did all her class assignments in just two weeks, and Ramesh did not complete his projects. 

By definition, had is the past tense of the word have. Had has a use to refer to a  previously possessed item or an anticipated outcome.

There are several instances of use in everyday life. For example, had I woken up late today, I would have missed the entrance to my board exams. 

Comparison Table

Parameters of Comparison	Did	Had
Meaning	Did refers to an irregular verb which is the simple past tense of the word do.	Had is an irregular verb which is the simple past tense of the word have.
Origin	The word did has its origin in the Latin word abdere. Abdere means to put away.	The origin of the word had is from the Latin word Habere. Habere means to own or to possess.
Main Use	Did has a practical application for the indication of a task that has already been completed.	In clear terms, the word had is used to indicate the possession of something a person no longer owns.
Alternate Use	Another prominent use of did is to avoid repetition in sentences.	Had may sometimes be used in the place of if.
Example	Siya did all the household chores by herself as her family was gone on a vacation.	I had ten pairs of shoes in the last one year.

What is Did?

Did refers to an irregular verb which is the simple past tense of the word do. Did has a practical application for the indication of a task that has already been completed.

For example, Ramesh did his school homework a week before the commencement of school. Another example is Siya did all the household chores by herself. 

The word did has its origin in the Latin word abdere. Abdere means to put away. In practical terms, the verb did can be put to use in sentences containing first persons, second persons, and third persons.

When the word did is combined with the word not, it conveys a negative connotation. For example, Rehaan did not attend school for the last two days. 

Another prominent use of did is to avoid repetition in sentences. In this case, did replaces a phrase or a verb phrase. For example, Seema had told me to submit her class assignment today, which I did, though I was late for my class.

Another example is Raven requested me to email him my gpay id, which I already did yesterday.

Did has a relevant use in question formation as well. For example, Did you check your messages today? Another example is Did you go to Raman’s party yesterday? Thus, did has use in interrogative sentences.

To conclude, did has multifaceted uses in several sentence types. 

What is Had?

Had is an irregular verb which is the simple past tense of the word have. Like any other verb, it performs the function of indicating the state of action. For example, Rahul had a considerable amount of wealth, but he is no longer rich.

Another example is that I had ten chocolates yesterday, but I gave all of them to my niece. 

Had may sometimes be put to use in the place of if. For example, had I studied hard, I wouldn’t have failed the exams. Another example is that had Sham spoken the truth, he wouldn’t have been punished with life imprisonment.

The origin of the word had is from the Latin word Habere. Habere means to own or to possess. 

There are several visible uses of had in everyday sentences. Example are had I taken admission to an average university, I would have regretted it my entire life.

Suman had all the qualities of an ideal psychologist, but her fame took a toll on her talents and skills. Thus, had has been used in multi-facet sentences. 

The word had is used to indicate the possession of something a person no longer owns. For instance, Reema had owned a doll set during her childhood years.

Another example is that I had ten pairs of shoes last year. Had has been used to refer to a  previously possessed item or an anticipated outcome. 

Main Differences Between Did and Had

1. Did refers to an irregular verb which is the simple past tense of the word do. In contrast, had is an irregular verb which is the simple past tense of the word have. 
2. The word did has its origin in the Latin word abdere. Abdere means to put away. On the other hand, the origin of the word had is from the Latin word Habere. Habere means to own or to possess.
3. Did has a practical application for the indication of a task that has already been completed. In contrast, the word had is used to indicate the possession of something a person no longer owns. 
4. Another prominent use of did is to avoid repetition in sentences. On the other hand, had may sometimes be used in the place of if. 
5.  Examples of did include Riya did all her class assignments in just two weeks. In contrast, an example of had includes had I taken admission to an average university, I would have regretted it my entire life.

References

1. https://www.really-learn-english.com/when-should-i-use-have-has-had-do-did-and-does.html 
2. https://www.myenglishteacher.eu/blog/what-is-the-difference-between-did-and-had/