Acts 18:11

He continued there a year and six months - He was now confident that he was under the especial protection of God, and therefore continued teaching the word, τον λογον, the doctrine of God. It is very likely, that it was during his stay here that he wrote his first epistle to the Thessalonians, and the second not long after; and some think that the epistle to the Galatians was written during his stay at Corinth.

And he continued ... - Paul was not accustomed to remain long in a place. At Ephesus, indeed, he remained three years Acts 20:31; and his stay at Corinth was caused by his success, and by the necessity of placing a church, collected out of such corrupt and dissolute materials, on a firm foundation.

18:11 He continued there a year and six months - A long time! But how few souls are now gained in a longer time than this? Who is in the fault? Generally both teachers and hearers.