In grammar, what is a matrix clause?

A matrix clause is a clause that surrounds an embedded clause. It is typically—but not always—the main clause of a sentence.

Example:

Jim’s old car, which was never any good in the first place, broke down yesterday.

• “Jim’s old car [...] broke down yesterday” is a matrix clause.
• “which was never any good in the first place” is an embedded clause.

SavoirFaire:

Thanks! Your answer was straightforward and clear. That’s all we need on Fluther.

@MarcoDemarco You are most welcome. Glad I could help!