Base vs Basis

When to use each in English, with meaning, register, and examples.

	Base	Basis
Meaning	The bottom part of something or a starting point for something.	The main reason or support for something.
CEFR level	B1	B1
Part of speech	noun	noun
Usage notes	Use 'base' in contexts related to foundations or starting points, like a base for an argument or a physical structure. Avoid using it in overly casual or slang contexts.	Used in discussions to refer to the fundamental reason or support behind ideas or actions. Common in academic and formal contexts, but can be used informally too. Avoid in casual conversation when discussing simple preferences.

Frequently asked questions: Base vs Basis

What's the difference between "Base" and "Basis"?

"Base" means: The bottom part of something or a starting point for something. "Basis" means: The main reason or support for something.

When should I use "Base" and "Basis"?

They can all be used in everyday English.

Are "Base" and "Basis" the same CEFR level?

"Base" is at B1, "Basis" is at B1 on the CEFR scale.