Meaning: In the ocean, octopuses conceal themselves from view behind solid pieces of mineral.
Choice of Words: Octopus: sea creature with eight arms; hide: conceal from view; rock: solid piece of mineral; ocean: large body of saltwater.
Alternative Expressions
The octopus hides behind the rock in the ocean.
Meaning: This means that the octopus is using the rock to hide from other animals or from people. It's like saying, The octopus is hiding behind the rock so that it can't be seen.
Choice of Words:The is a definite article that refers to a specific noun. Octopus is a type of sea creature with eight arms. Hides means to put something out of sight or to keep it secret. Behind means at the back of something. The is a definite article that refers to a specific noun. Rock is a hard, solid substance that forms part of the earth's surface. In means inside or within something. The is a definite article that refers to a specific noun. Ocean is a large body of salt water that covers most of the earth's surface. When you put them together, "The octopus hides behind the rock in the ocean" means that a specific octopus is hiding behind a specific rock in the ocean.
An octopus is hidden behind a rock in the ocean.
Meaning: This means that there is an octopus hiding behind a rock in the ocean, but we don't know which specific octopus or which specific rock. It's like saying, There is an octopus hiding behind a rock in the ocean, but I don't know which one.
Choice of Words:An is an indefinite article that refers to a non-specific noun. Octopus is a type of sea creature with eight arms. Is is a verb that means to exist or to be. Hidden means to be put out of sight or kept secret. Behind means at the back of something. A is an indefinite article that refers to a non-specific noun. Rock is a hard, solid substance that forms part of the earth's surface. In means inside or within something. The is a definite article that refers to a specific noun. Ocean is a large body of salt water that covers most of the earth's surface. When you put them together, "An octopus is hidden behind a rock in the ocean" means that a non-specific octopus is hidden behind a non-specific rock in the ocean.