Some verbs need a little bit of extra help. And that is where helping verbs come in. In these more complex tenses, helping verbs are necessary to change the tense or the mood of the sentence. So for example, the word “be” is used to form the progressive tenses. Progressive tenses describe ongoing actions, things that are happening right now. “I am writing my KAM.” I am doing it right now, I am working on my KAM.
The word “have” describes what’s called the perfect tenses. Now perfect tenses indicate that an action has happened before another action or event or time. So for example, “She has worked at the school for 12 years.” Now, I want to talk about this tense a little bit more because this one is a little bit tricky. This sentence might seem quite similar to the simple past tense. “She worked at the school” versus, “She has Worked at the school.” But there’s a really sort of subtle difference here. If I were to say “She worked at the school for 12 years,” it sounds as though she worked there, but she no longer works there. If I say “She has worked at the school for 12 years”, that indicates that she still does work there. She’s been there for 12 years and she still is there. This is sort of a tricky difference. It can be pretty subtle. And so my main point here is that you want to pay attention to the verbs in your sentences and make sure they’re saying what you want them to say.
Finally, the word “do” is a helping verb that helps emphasize words in a sentence. So for example, “Despite the student’s complaining, the teacher does grade fairly.” It just helps to emphasize, to stress, that word in the sentence.
[Source: Walden University. https://academicguides.waldenu.edu/c.php?g=465757&p=3437710%5D