The plural form of potato is potatoes. The plural form of tomato is tomatoes. There are many rules in English for the construction of plural nouns, potatoes and tomatoes are examples of plural nouns that are exceptions to a rule. Some dictionaries list the word potatoe as a variant spelling of potato, this variation doesn’t appear to be wide-spread.
In general, nouns that end in -o form plurals by simply adding -s, such as volcanos, tacos, zoos. Potato and tomato belong to a set of nouns that end with the letter -o that form plurals by adding -es. Other plurals formed by adding -es to words ending with -o are echoes, torpedoes and vetoes.
Potatoes are the vegetable that take breakfast, lunch, dinner and snacks to the next level of yum. (The Las Vegas Review-Journal)
Since any cream, milk or broth should be warmed first (more on this later) before adding it to the potatoes, add the garlic to any of these as they warm. (The Times Record)
However replacing three servings of potatoes a week with wholegrains – such as rice, quinoa, wheat and corn – could lower the risk of type 2 diabetes by 12 per cent, researchers concluded. (The Daily Mail)
Tomato juice in the United States is often made from tomato paste, but Canadian regulations require fresh tomatoes. (The New York Times)
The price of tomatoes, which surged higher after a hot, dry summer and then retreated, is climbing higher again just three months later because of a virus that is taking a heavy toll on the local crop. (Haaretz)
Israel on Tuesday dispelled the notion that several tons of Gaza-produced tomatoes were rejected from import because they were found to contain carcinogenic chemicals. (The Times of Israel)