
428 S.E.2d 853 (1993)
110 N.C. App. 91
STATE of North Carolina,
v.
Manley Jarvis GUTHRIE, Defendant.
No. 9210SC214.
Court of Appeals of North Carolina.
May 4, 1993.
Atty. Gen. Lacy H. Thornburg by Sr. Deputy Atty. Gen. Isham B. Hudson, Jr., Raleigh, for the state.
John T. Hall, Raleigh, for defendant appellant.
ARNOLD, Chief Judge.
Defendant's first argument is that the court erred by not allowing him to cross-examine the victim about the letter. Effective cross-examination is a fundamental right and "is denied when a defendant is prevented from cross-examining a witness at all on a subject matter relevant to the witness's credibility." State v. Durham, 74 N.C.App. 159, 163, 327 S.E.2d 920, 923 (1985). The denial of that right "is constitutional error of the first magnitude *854 and no amount of showing of want of prejudice would cure it." Id. But, the defendant's right to cross-examination is not absolute. The testimony which defendant sought to elicit must be relevant to some defense or relevant to impeach the witness. Durham, 74 N.C.App. at 167, 327 S.E.2d at 926.
N.C.R.Evid. 412 is "a codification of the `rule of relevance' as it pertains to issues in a rape case." State v. Younger, 306 N.C. 692, 697, 295 S.E.2d 453, 456 (1982). Rule 412 provides that evidence of sexual behavior of the complainant is irrelevant unless it falls within one of four categories listed in the rule. N.C.R.Evid. 412(b)(1)-(4). Our Supreme Court, however, has held that Rule 412 is not the sole gauge in determining if evidence is admissible in rape cases. Younger, 306 N.C. at 698, 295 S.E.2d at 456. The victim's statements about prior specific sexual activity is sometimes admissible to impeach the victim even though the statements do not fall within Rule 412(b)(1)-(4). Id. at 698, 295 S.E.2d at 456-57.
The State objected to the testimony about the letter on the basis of Rule 412. The trial judge sustained the objection, apparently believing that Rule 412 rendered the testimony irrelevant and inadmissible. However, testimony about the letter is not the type of evidence which Rule 412 seeks to exclude. Rule 412 is concerned with sexual activity of the complainant. N.C.R.Evid. 412(a). We do not have evidence of sexual activity here. Instead, we have evidence of language.
We previously held that language or conversation is not sexual activity. See Durham, 74 N.C.App. at 167, 327 S.E.2d at 926 (child's accusation of her father to the extent it was evidence of conversation was not excluded by Rape Shield Statute), State v. Baron, 58 N.C.App. 150, 153-54, 292 S.E.2d 741, 743-44 (1982) (prior false accusations of improper sexual advances not prohibited by Rule 412). In State v. Smith, 45 N.C.App. 501, 263 S.E.2d 371, disc. review denied, 301 N.C. 104 (1980), we held that conversation between complainant and defendant concerning complainant's sexual problems with another man did not rise to the level of sexual behavior. Smith, 45 N.C.App. at 503, 263 S.E.2d at 372 ("While the topic of conversation may have been sexual in nature, there is no evidence presented in this case to indicate that the speech rose to the level of sexual behavior or activity...." Id.).
Likewise, in this case, defendant's evidence is evidence of conversation, not of a sexual act. Therefore, testimony concerning the letter is not deemed irrelevant by Rule 412 and was improperly excluded on that basis.
The remaining question is was testimony about the letter relevant to impeach the credibility of the victim. As in most sex offense cases, the victim's testimony is crucial to the State's case and her credibility can easily determine the outcome of the trial. Showing that the victim voluntarily wrote at least one letter to another person which is similar to the ones written to defendant bears directly on the victim's credibility. It infers that the victim wrote the letters to defendant voluntarily, contradicting her earlier testimony. Defendant had a right to develop this contradictory testimony on cross-examination, and denial of that right was reversible error.
Because we find reversible error in the limitation of defendant's cross-examination and because the evidentiary issues raised in defendant's remaining arguments may not arise at the second trial, we do not address defendant's remaining arguments.
New trial.
COZORT and LEWIS, JJ., concur.
