This psalm contains both corporate hymnic praise (vv. 1–12) and individual thanksgiving (vv. 13–20). Some commentators (e.g., H.-J. Kraus, Psalms 60–150, vol. 2 of Psalms, A Commentary [trans. H. C. Oswald; Minneapolis: Augsburg, 1989], p. 36), thus believe it consists of two psalms (or their fragments) that were originally separate. But several linguistic features imply they were composed together:

Verses 1–12 / Verses 13–20  

“Come and see what God has done, “Come and listen, all you who fear God;   how awesome his works in man’s behalf!” (v. 5) / let me tell you what he has done for me” (v. 16).  

“Praise our God, O peoples, “Praise be to God, and let the sound of his praise (Hb. tehillātô) be heard” (v. 8) / who has not set aside my prayer (Hb. tepillātî), or withheld his love from me…