さつまいもって英語でなんて言うの？

This vegetable is known as a sweet potato.

In some cultures it may be referred to as a yam but it is known widely as a sweet potato.
The skin can vary in colour from red, brown or purple.

She always cooked with sweet potatoes.
It was a tasty sweet potato pie.

I hope that helps!

White potatoes..."The common or garden variety" ... is not the same plant at all;-)
Sweet potatoes & White potatoes have nutritional differences; however one isn't
necessarily better than the other;-D
Sweet potatoes have more fiber and vitamin A, but white potatoes are higher in
essntial minerals, such as iron, magnesium, and potassium.

▪Sweet potato
The sweet potato is large, starchy, sweet-tasting, root vegetable.

Example
a. Hey, would you like to have some sweet potato fries?
b. Do you like sweet potatoes?

In English, a potato which is sweet and has a bright orange or purplish color is called
a sweet potato.
For example:
>Last night we had some sweet potatoes with our dinner.

Sometimes, people also call a sweet potato a 'yam'.
For example
>My friend's mother cooks the best-boiled yams!
Yam is a term used mainly in the United States and comes from an African word 'nyami' which means sweet potato.

---> Sweet potatoes are vegetables that look like large ordinary potatoes but taste sweet. They have pinkish-brown skins and yellow flesh.

• Cut into cubes and boil a large sweet potato.
  -Serve with sweet potatoes roasted in the skins while the stew cooks
  -Wash the sweet potatoes and bake whole until soft.
  -Dish these up with roasted sweet potato wedges and extra lime wedges.

Sweet potato
- It is most widely known as a sweet potato, if you want to be more descriptive you could say "sweet potato with purple skin". Both are correct.

Yam
- In the U.S.A. a lot of people refer to sweet potatoes as yams even though they're not really yams. But in the US they're considered to be pretty much the same thing. If you called this vegetable a yam no one would blink an eye at you. Also if someone tells you they're making yams, they probably mean they're making sweet potatoes.

"Hey Susan! Do you wantb to know my secret?"
"What secret is taht then?"
"How I get my mash potato to taste so brilliant!"
"Ummm, OK. How dom you do that? Add milk and butter, I suppose?"
"Well, yes, I add milk and butter and salt and pepper ,- but also one or two sweet potatoes."
"Why do you do that?"
"It makes the mixture a little sweeter, of course...but also adds a little colour."
"I'll try that myself next time!"

Satsumaimo is called "Sweet potato" in English. So when you speak about it, you can say:
-I prefer grilled sweet potato chips because they are healthier and taste better.
-I don't like sweet potato.

Native speakers call it sweet potatoes.

The singular term is sweet potato and if it is more that one we say "sweet potatoes"

• My favorite vegetable is sweet potatoes.

Sweet potato skin can be white, yellow, red, purple or brown, and the flesh can be white, yellow, orange or purple.
Sweet potato is delicious and so many different dishes can be made using it as the main ingredient.
As its name explains, it is sweet in taste and it has a soft, potato-like texture.

Flesh: the part of the fruit you eat, inside the skin/peel
Texture: what something feels like