'Else if you bless with the spirit, how shall he who fills the place of the unlearned say the Amen at your giving of thanks, seeing that he does not know what you are saying? For you truly give thanks well, but the other is not edified.'
He confirms the point made in 1 Corinthians 14:15 by pointing out yet again that if an individual 'blesses' with his spirit in tongues, that is offers praise, worship and thanksgiving, those who are there as 'unlearned', will be unable to respond to his giving of thanks to God, because they will not know what he is saying. While he will be giving thanks well, (something he could do equally well in private), because he is, if the gift is a true one, Spirit inspired, no one else will be edified.
We could in fact argue that actually in such a case (of insisting on using uninterpreted tongues in public) it will be questionable whether the tongues are Spirit inspired, for it is hardly likely that the Spirit would inspire selfish praying which is now seen as forbidden. That is why we must translate with a small 's'.
'How shall he who fills the place of the unlearned say the Amen at your giving of thanks.' We note here that the one described as 'unlearned' would be expected to say 'Amen' and will fail to be edified or built up. This would point to such a person being a Christian. This might suggest that the person is so described simply because they cannot understand the tongues. 'Unlearned' may even have been a slightly derogatory term used by those who spoke in tongues of those who did not.
Others point to 1 Corinthians 14:24 and consider that it probably means those who have not yet full understood and responded to the Christian faith. This might then suggest that special places were reserved for such. Then it would demonstrate that Paul was especially concerned for them. He would see it as tragic if they were put off by too much in the way of tongues. It would in his eyes be important that they could participate in the worship and understand sufficient to be able to say 'Amen', that is, indicate their agreement and participation.
Or in view of the reference to edifying it may mean the Christian novices. But whichever it means the point is the same. The word actually connects with a root which can indicate someone not particularly trained, the ordinary person in contrast to the trained expert, although there is some evidence for a technical meaning as signifying one who still attended pagan worship but was interested in Christianity.
His assumption that the church will say 'Amen', a Hebraism, is interesting. 'Amen' was said in synagogue services in response to prayers (compare Psalms 106:48; 1 Chronicles 16:36; Nehemiah 5:13; Nehemiah 8:6). This would tend to indicate that to quite some extent church worship was patterned on synagogue worship.