Should the Great Commission in Matthew 28:19 be rendered, “Go and make disciples,” or “As you go, make disciples”?
The word translated “go” is the participle πορευθέντες. Participles are similar to words in English that end in -ing or –ed, and they have the form of both a verb and an adjective. Πορευθέντες is a verbal participle in relation to the main verb μαθητεύσατε: “make disciples.” As Merkle states, verbal participles like πορευθέντες often function as main verbs or verbs that are coordinate with a main verb. These participles can take on the mood of the main verb and become parallel to it. An example would be Luke 17:19 when Jesus tells the leper, “rise and go your way, your faith has made you well.” Rise (Ἀναστὰς) is a participle parallel to the main verb go (πορεύου). This use of the participle is called attendant circumstance.
Although some view πορευθέντες as a temporal participle (describing the “when” of the main verb) and translate the verse “as you go, make disciples,” most scholars say the evidence points to the attendant circumstance use of the participle in Matthew 28:19. Thus the participle πορευθέντες takes on the mood of μαθητεύσατε (an imperative), and becomes parallel to it. It should then be rendered as a command parallel to the main verb ‘make disciples,’ “Go and make disciples…”
Merkle concludes, “while we acknowledge that the participle πορευθέντες is not the main verb (and not the main command) in the Great Commission, without doubt it carries an imperatival force (“Go!”). Consequently, the church is given a command to go to the nations in order to make disciples.”
 Benjamin Merkle, Exegetical Gems from Biblical Greek, (Grand Rapids, MI: Baker Academic, 2019), 99-101.