Underwent or Undergone? Correct Past Tense of "Undergo"

Often in English, you’ll hear two words that seem to fulfill the same purpose, and you’ll be unsure as to which one is the correct one to use. Should you use “underwent” or “undergone” as the past tense of “undergo”? Are both allowed? This article will answer these questions.

Is Underwent or Undergone the Past Tense of “Undergo”?

The past simple tense of “undergo” is “underwent”, and the past participle is “undergone”. Both are accurate and valid, though they’re used in fairly different contexts. Even in spite of the fact that they’re both technically past tense, they’re not interchangeable at all.

You use “underwent” in situations where you’re simply talking about an event that happened in the past, with not much more complication in the formulation of a sentence.

Meanwhile, “undergone” would be mainly used for the past participle, in which you’re crafting the perfect form of verbs to talk about, in this case, something that happened in the past.

“Undergone” is perfect for situations in which you’re talking about a past action that is still somehow ongoing or relevant in the present in some specific way.

Underwent

“Underwent” is the past simple form of the verb “undergo”, and it’s the one that you’d default to when talking about something that you underwent. It would normally be used to talk about an isolated incident in your or someone else’s past.

“Underwent” is as simple as it gets when you’re talking about the verb “undergo”. You can use “underwent” to talk about a completed action in your past.

In case you’re curious about how to use “underwent”, here are some example sentences that will teach you:

I underwent surgery last year for my shoulder, and it thankfully went well.
She underwent training for this new job she got, and for a week it was all she talked about.
He underwent a terrible experience last year involving a car accident, sadly.
They underwent some really terrible weather last week so I hope they’ll be alright tonight.
We underwent one of the hardest years for our organization last year, and this year will be better.
I underwent several months of physical therapy following my accident, though I’m ok now.
She underwent terrible harassment for months on end, without anything being done to help her.

Undergone

“Undergone” is what is known as the “past participle” form of the verb. It’s not exactly a straightforward verb tense, because you can’t use it all on your own. You need an auxiliary verb, typically “has”, to use the past participle.

You use “undergone” in the past participle to talk in the past perfect verb tense, which in turn is used when you want to talk about something fully in the past.

Here are some example sentences that include “undergone” in them so you can learn how to use it:

He has undergone several episodes similar to this one, and we really want to get him some help.
She has undergone many tough battles and came out stronger every single time, which is good.
I have undergone surgery for my throat issues a couple of times in the past months.
They have all undergone training for their specialized job as delivery people, which isn’t easy.
I have undergone special training to ensure that my typing skills are better than everyone else’s.
He has undergone some very unfortunate events in his personal life, but he’s stronger for them.
She has undergone extensive interviews about her background and her personal essay’s details.

Which Is Used the Most?

According to the Google Ngram Viewer, “undergone” is more popular than “underwent” by a very small margin. The information showcases the fact that since the year 1900, “undergone” has been more popular than “underwent” for most of that time.

An interesting fact about this information is that for a few years, from 2009 to 2016, “underwent” briefly became more popular than “underwent”. It’s impossible to know exactly why this happened.

Had Undergone or Had Underwent?

You should use “had undergone” and avoid using “had underwent”, as the former is grammatically correct and the latter is awkward and incorrect. “Undergone” is the past participle, so you use it with an auxiliary verb such as “have”, which isn’t the case with “underwent”.

You use a verb tense like “underwent” on its own, without the help of an auxiliary verb like “have”.

Here are a few examples that showcase this fact:

Correct: She had undergone the surgery a few years back.
Incorrect: I had underwent specialized training last week.
Correct: He had undergone harassment recently for his article.
Incorrect: They had underwent terrible weather in the past month.