This is an update/revision/correction to the post yesterday, “Suppletive forms, verbs with multiple roots.” Some revisions are relative minor, others more substantive. Comments, corrections, additions are welcome.
All the Greek verbs that have different roots in Koine are given below.
• λέγω, “I say”
*λεγ (present) λέγω
*ϝερ/*ϝρη (future, perfect, aorist passive) ἐρῶ, εἴρηκα, ἐρρέθην
*ϝεπ (aorist active) εἶπον
• ἔρχομαι, “I come”
*ἐρχ (present) ἔρχομαι
*ἐλευθ/*ἐλθ (future, aorist, perfect) ἐλεύσομαι, ἦλθον, ἐλήλυθα
• ἐσθίω, “I eat”
*ἐσθι (present) ἐσθίω
*φαγ (future, aorist) φάγομαι, ἔφαγον
• ὁράω, “I see”
*ϝορα (present, perfect) ὁράω, ἑώρακα
*οπ (future, aorist middle, aorist passive) ὄψομαι, ὠψάμην, ὤφθην
*ϝιδ (aorist active, aorist active infinitive) εἶδον, ἰδεῖν
• φέρω, “I carry”
*φερ (present) φέρω
*οι (future) οἴσω
*ενεκ (aorist active, aorist passive, perfect) ἤνεγκα/ἤνεγκον, ἠνέχθην ἐνήνοχα
Less Common Words with Multiple Roots
• αἱρέω, “I choose”
*αιρε (present, future, perfect middle, aorist passive) αἱρέω, αἱρήσομαι, ᾕρημαι, ᾑρέθην
*ϝελ/*ϝαλ (aorist active) εἱλόμην/εἱλάμην
• πάσχω, “I suffer”
*παθ (present, aorist) πάσχω, ἔπαθον
*πενθ (future, perfect) πείσομαι, πέπονθα
• πίνω, “I drink”
*πι (present, future, aorist) πίνω, πίομαι, ἔπιον
*πο (perfect) πέπωκα
• τρέχω, “I run”
*θρεχ (present) τρέχω
*δραμ/*δρομ (future, aorist, perfect) δραμοῦμαι, ἔδραμον, δεδράμηκα
Notes
The convention used here is to identify a root with a prefixed asterisk. You will never see any Greek text that is marked in this way appearing as a separate word; there will always be prefixes or suffixes added and many times there will also be vowel ablaut (sometimes called vowel gradation) as well.
Verbs which use different roots may be called defective verbs (the individual roots do not occur in all tense-forms) or suppletive forms (the various roots supplement each other to enable a full range of tense-forms). Both defective and suppletive are larger category terms that may refer to items other than verbs having multiple roots.
This also happens in other languages, including Latin: fero, tuli, latum, ferre (= φέρω); sum, esse, fui (= εἰμί); and Hebrew: יָטַב and טוֹב, “to be good.” (See GKC, 220, §78.b. for more examples in Hebrew.)
The same thing happens in English. The word go (present tense) and went (past tense) are not etymologically related. English formerly had a past tense of go (eode, Anglo-Saxon; yode in Middle English). It also had a present tense of went, the form wend. This last word still occurs in English, though rarely. You will sometimes read it in poetry where it enables the poet to maintain the rhyme. We now use go and went as if they are present and past tenses of the same word even though they are unrelated etymologically.
οἶδα is sometimes listed as a word having multiple roots, but it is an irregular μι- verb (ἴδοιμι) formed from the root *̈ϝιδ, though it may appear to have other roots due to ablaut.
Although the list above aims to be fairly complete for Koine texts (at least those related to the NT (LXX, pseudepigrapha, Josephus, Philo), other Greek texts may have other suppletive forms. Although the middle-only form ὠνέομαι, “I buy,” has one first aorist in the NT, ὠνησάμην/ὠνήσατο, formed from *ωνε, in classical Greek there was a suppletive second aorist form, ἐπριάμην (from *πρια).
Also τύπτω (present and imperfect) is supplemented by πατάσσω and sometimes by παίω (for the future and aorist) and πλήσσω (perfect and aorist passives). Likewise σκοπέω (present and imperfect only) is supplemented by σκέπτομαι (cf. NT ἐπισκέπτομαι). The verb θεωρέω (present and imperfect) is supplemented by θεάομαι (aorist and perfect). This last pair (θεωρέω, θεάομαι) also functions suppletively in the NT, though the words are treated separately in NT lexica.
Suppletion can also function at the voice level, e.g., in the LXX the verb ἁλίσκομαι, “to be taken, captured,” occurs only in the passive with the active being supplied by αἱρέω (both from the same root, *ϝελ/*ϝαλ).
Resources
Smyth, Grammar, esp. §§529, 794–99, and the Appendix, “List of Verbs” (pp. 684–722)
BDF, Grammar, §101, “Catalog of Verbs,” pp. 50–55
Mounce, Morphology of Biblical Greek, “Class v-8,” p. 319.