- Benefited and benefitted are both acceptable spellings.
- Benefited</ is more common in the United States.
When you make a verb past tense, sometimes all you have to do is add -ed. Other times, you double the final consonant before adding it. What about the verb benefit? Is the past tense benefited or benefitted?
Benefited vs. Benefitted
The quick answer is that both of them are acceptable. However, you might wonder why the double T version exists in the first place. What’s the rule for doubling the final consonant for the simple past? For regular verbs, you double the last consonant when a one-syllable verb ends in a consonant-vowel-consonant pattern. If a verb has more than one syllable, you double the last consonant if it is in a stressed syllable. Does benefit fit the rule?
Is the ending in a consonant-vowel-consonant pattern? Yes, F-I-T are the last three letters.
Is the verb one syllable? No, benefit is three syllables. So now, you would only double the last consonant if it’s stressed. Is it stressed? That answer is not so cut-and-dried. Benefit sounds a little different in British and American English. Some say that the final F-I-T is unstresssed in American English. By that criterion, you can write the past tense of benefit as benefited. In the United States, this is the most common way to spell it.
Why would anyone spell benefitted with a double T? Well, even native English speakers might not know all the rules that govern the language. Another verb, fit, does double the T in the past tense because it is one syllable. So it’s easy to see why people might think benefit is like fit in the past tense. Others say the final syllable of benefit receives a secondary stress, so perhaps that’s reason enough to apply the stressed last syllable rule.
Benefited and Benefitted Examples
Would you like to see benefited and benefitted in context? Let’s look at some examples from books and online. Which way of writing it seems right to you?
If you are in favor of spelling the past tense of benefit with one T, you are part of the majority in the United States. However, if you think that the final T should be doubled, you are definitely not alone. You can spell it either way, but be prepared; your choice might result in a friendly debate!
from Grammarly Blog https://www.grammarly.com/blog/benefited-or-benefitted/