The Greek verb γέγονα is a form of γίνομαι: γέγονα is the perfect indicative active first-person singular form of γίνομαι, which means it signifies completed action performed by an agent. Notice how 1 Corinthians 13:1 has "I have become" for γέγονα or "I am become" (KJV). So the action is completed, it really happens (hence, the indicative), and it's first person singular ("I). Compare 1 Corinthians 13:11.
HCSB: "If I speak human or angelic languages but do not have love, I am a sounding gong or a clanging cymbal."
Paul Gardner (1 Corinthians, ZECNT): "Love, as Paul describes it here, is not an extra special grace-gift but is what marks all who are possessed by the Spirit. Gifts being exercised in a context where this is not present, where self is first and God and neighbor second or third, where status is sought rather than humility seen, make the person simply irrelevant spiritually. The person has become like random noise, which has no purpose or meaning. The verb meaning 'to become' or 'to be' (γέγονα) is in an intensive perfect. The present results are what matters to Paul. If this person spoke in this way, without love, then he or she has become or simply is a noisy gong. What Paul is saying is clear thus far."
Intensive Perfect Definition (Daniel Wallace, GGBB, page 574): "The perfect may be used to emphasize the results or present state pro-duced by a past action. The English present often is the best translation for such a perfect. This is a common use of the perfect tense."
