Complete to Do vs. Doing – Which is Correct?
When using complete as a verb, follow it with a gerund: complete doing something. Do not normally use complete to do something. For example, write “She completed writing the report,” not “She completed to write the report.” Use to do after verbs including want, plan, or need in appropriate contexts.
Complete to Do or Doing – Which is Correct?
Complete doing is the grammatically correct construction when complete means to finish an activity. The word doing is a gerund, or an -ing form functioning as a noun, so it can serve as the object of complete.
Complete to do is not normally correct when complete is the main verb. English does not generally use complete followed directly by a to-infinitive. Use a noun, an -ing form, or a different verb instead: “I completed the assignment,” “I completed doing the assignment,” or “I finished doing the assignment.”
The Best Trick to Remember the Difference
Use the finish test. If you can replace complete with finish, use an -ing form: “I finished doing the work,” so “I completed doing the work” is possible too. However, if you want to express an intention or obligation, use to do after verbs such as want, plan, or need: “I need to do the work.”
| Word or Construction | Part of Speech | Meaning | Example |
|---|---|---|---|
| complete doing | Verb + gerund | Finish an activity | She completed doing the required training. |
| complete to do | Incorrect verb pattern | Not normally used to mean “finish doing” | Avoid: She completed to do the training. |
How to Use Doing
Doing is the -ing form of the irregular verb do. It can function as a gerund, a present participle, or part of a continuous verb phrase. After complete, it functions as a gerund because it names the activity being finished.
The construction complete doing is grammatically possible, but it is sometimes less natural than complete followed by a direct noun. In many situations, “I completed the form” sounds smoother than “I completed filling out the form.” Still, when the activity itself needs emphasis, complete doing is clear and correct.
Example 1: The students completed doing the safety exercises before lunch.
Example 2: She completed doing the inventory and sent the results to her manager.
Example 3: After completing doing the online training, employees received a certificate.
What are the Different Forms of Doing?
Doing is a form of the irregular verb do. The principal forms are do, does, did, and done. The form doing serves as both the present participle and the gerund.
- Present: I do the work. She does the work.
- Past: They did the work yesterday.
- Past participle: We have done the work.
- Present participle or gerund: They are doing the work. Doing the work requires concentration.
Etymology of the Word Doing
Doing comes from the Old English verb dōn, meaning “to put, place, perform, or cause.” The verb developed into Middle English don and eventually modern English do. The ending -ing creates the form used for ongoing actions and activities treated as nouns.
Related Concepts
Understanding verb patterns makes it easier to choose between doing and to do. Different verbs select different complements, so a pattern that follows one verb may not follow another.
Comparing these patterns with Help Do clarifies why English verbs can take different complements.
- Gerunds: A gerund is an -ing verb form used as a noun. In “complete doing the work,” doing identifies the activity that was completed.
- To-infinitives: A to-infinitive consists of to plus the base form of a verb, as in “to do.” It commonly follows verbs such as want, hope, plan, and need.
- Verb complements: A verb complement is the word or phrase that completes a verb’s meaning. Some verbs take gerunds, some take infinitives, and others can take either form.
- Direct objects: A direct object receives the action of a verb. In “complete the report,” report is the direct object; in “complete doing the report,” the gerund phrase functions as the object.
Examples from Media and Literature
The correct choice depends on the verb that comes before the phrase. These examples reflect common patterns found in workplace writing, journalism, fiction, and everyday dialogue:
- Workplace communication: “The team completed reviewing the safety procedures before the meeting began.”
- News reporting: “Investigators completed examining the evidence at the scene.”
- Educational writing: “After completing the experiment, students recorded their observations.” This version uses a noun phrase and is often more concise than “completing doing the experiment.”
- Fictional dialogue: “I need to do this before dinner,” uses to do correctly after need, not after complete.
- Project instructions: “Complete filling out every section of the application before submitting it.” In polished writing, “Complete every section of the application” is usually more natural.
Doing Synonyms
| Synonym | Definition |
|---|---|
| Performing | Carrying out an action, duty, or task. |
| Carrying out | Completing or implementing a plan, instruction, or responsibility. |
| Undertaking | Beginning or accepting responsibility for a task or project. |
| Handling | Managing or dealing with a task, situation, or responsibility. |
| Accomplishing | Successfully completing a task or goal. |
Frequently Asked Questions
Question 1: Is it correct to say “complete to do”?
No. When complete means “finish,” it should not normally be followed directly by a to-infinitive. Use “complete doing,” “complete the task,” or “finish doing” instead.
Question 2: Is “complete doing” always natural?
It is grammatically correct, but it can sound wordy in some sentences. “I completed the report” is often more natural than “I completed writing the report.” Use complete doing when focusing specifically on the activity.
Question 3: When should I use “to do”?
Use to do after verbs that commonly take infinitives, including want, need, plan, hope, and decide. For example, “They plan to do the work tomorrow” is correct.
Conclusion
Use complete doing, not complete to do, when describing the completion of an activity. Remember that complete can take a noun or a gerund, while to do belongs after verbs such as need, want, and plan. Pro Tip: Choosing the correct verb pattern strengthens your grammar and helps your professional writing appear polished and credible.
