Pluto was once considered the ninth planet.

Meaning: Pluto used to be thought of as the ninth planet in our solar system.

Choice of Words: Pluto is the name of a celestial body. Was is a past tense of the verb be. Considered means to regard or think of something in a particular way. Ninth means the number 9 in order. Planet is a large celestial body that orbits a star.

Alternative Expressions

Pluto was once thought of as the ninth planet.

Meaning: In the past, people believed that Pluto was the ninth planet from the sun. But now we know that Pluto is actually a dwarf planet.

Choice of Words: The word "was" shows that this is something that happened in the past. "Once" means that it happened one time. "Thought of" means that people believed something to be true, even if it wasn't. "Ninth" means the number 9. "Planet" is a big ball of rock or gas that goes around a star.

Pluto used to be known as the ninth planet.

Meaning: In the past, Pluto was called the ninth planet from the sun. But now we know that Pluto is actually a dwarf planet.

Choice of Words: The word "used to" shows that this is something that happened in the past and is no longer true. "Known as" means that something is called or identified by a particular name. "Ninth" means the number 9. "Planet" is a big ball of rock or gas that goes around a star.

Pluto was mistakenly considered the ninth planet.

Meaning: In the past, people made a mistake and thought that Pluto was the ninth planet from the sun. But now we know that Pluto is actually a dwarf planet.

Choice of Words: The word "mistakenly" means that something was done by mistake. "Considered" means that something was thought to be true, even if it wasn't. "Ninth" means the number 9. "Planet" is a big ball of rock or gas that goes around a star.

Related Expressions