“And he continued there a year and six months, teaching the word of God among them.”
King James Version (KJV)
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.
Ac 18:11 He continued [there] a year and six months. While here, besides his other labors, he wrote the two epistles to the Thessalonians, the first of that grand series of letters which form so precious a feature of the New Testament.