She came seldom than you expectedis it simple or compound sentence?

Here's why:

* "Seldom" is an adverb, not an adjective. You need to use a comparative adjective like "less often" or "rarer".

* The sentence structure is incorrect. The correct structure would use a comparative adjective: "She came less often than you expected."

Here's how to correct it:

* "She came less often than you expected." (Simple sentence)

Simple Sentence: A simple sentence has one independent clause (a complete thought with a subject and verb).

Compound Sentence: A compound sentence has two or more independent clauses joined by a coordinating conjunction (e.g., and, but, or).