In Ancient Greek grammar, movable nu or movable N (Ancient Greek: νῦ ἐφελκυστικόν nû ephelkystikón, literally "nu dragged onto" or "attracted to") is a letter nu (written ν; the Greek equivalent of the letter n) placed on the end of some grammatical forms in Attic or Ionic Greek. It is used to avoid two vowels in a row (hiatus) or to create a long syllable in poetic meter.
Grammatical forms 
Movable nu may appear at the end of certain forms of verbs, nouns, and adjectives. In grammatical paradigms, it is usually written with a parenthesis to indicate that it is optional.
|third person plural present and future|
|λέξουσι(ν)||"they will say"||future|
|third person singular perfect and past|
|τέθνηκε(ν)||"he has died", "is dead"||perfect|
|ἔλεγε(ν)||"he was saying"||imperfect|
|ἐτεθνήκει(ν)||"he had died", "was dead"||pluperfect|
|third person singular present
|third declension dative plural|
Movable nu is used before words starting in a vowel to prevent hiatus.
- πᾶσιν ἔλεγεν ἐκεῖνα "he said those things to everyone"
It is omitted before consonants.
- πᾶσι λέγουσι ταῦτα "they say these things to everyone"
It is often used at the end of clauses or verses.