How have the courts interpreted the Miranda rights?

Defendant contends: (1) He invoked his Miranda rights, requiring Officer Bezuglov to cease interrogation. (2) Even if defendant's invocation was ambiguous, Officer Bezuglov improperly failed to seek clarification. (3) A waiver cannot be established in any event because the record fails to show defendant understood his right to counsel. (4) The erroneous admission of defendant's statements was prejudicial under the standard of Chapman v. California (1968) 386 U.S. 18, 24 [17 L.Ed.2d 705]. We are not persuaded.