Spelling rule for ence and ance?

There isn't a strict spelling rule for "ence" and "ance," but here's a way to think about it:

"ence" is often used when the root word comes from a Latin word ending in "entia" or "enti".

Examples:

* Absence (from the Latin "absentia")

* Presence (from the Latin "presentia")

* Confidence (from the Latin "confidentia")

* Difference (from the Latin "differentia")

"ance" is often used when the root word comes from a Latin word ending in "antia" or "anti".

Examples:

* Importance (from the Latin "importantia")

* Guidance (from the Latin "gubernantia")

* Assistance (from the Latin "assistentia")

* Distance (from the Latin "distantia")

However, there are exceptions to these general rules:

* Some words that end in "ence" are derived from French words. Examples: "influence," "innocence," "excellence."

* Some words that end in "ance" are derived from words that don't follow the Latin pattern. Examples: "advance," "chance," "romance."

The best way to learn the spelling of words ending in "ence" or "ance" is to simply memorize them.