You are absolutely right to notice that difference! It's a common point of confusion. Here's the breakdown:

* Something is a pronoun, meaning it takes the place of a noun. It refers to an unspecified object or idea.

* Example: "I need something to eat." (We don't know what they want to eat, just that they want food.)

* Some thing is two words: an adjective ("some") and a noun ("thing"). It refers to an unspecified object or idea, but in a more specific way.

* Example: "Could you grab some things from the store?" (The speaker implies there are multiple objects they need.)

Here's a quick way to remember the difference:

* Something is one word and refers to a single, unspecified thing.

* Some thing is two words and refers to a specific, yet unspecified, group of things.

Hopefully that clarifies the difference!