Herbert Weir Smyth, A Greek Grammar for Colleges

THE ADJECTIVE PRONOUNS ἄλλος AND ἕτερος

a. ἕτερος is sometimes used loosely for ἄλλος, but always with a sense of difference; when so used it does not take the article.

[*] 1272. ἄλλος, and ἕτερος (rarely), may be used attributively with a substantive, which is to be regarded as an appositive. In this sense they may be rendered besides, moreover, as well: οἱ ἄλλοι Ἀθηναῖοι the Athenians as well (the others, i.e. the Athenians) T. 7.70, ““τοὺς ὁπλί_τα_ς καὶ τοὺς ἄλλους ἱππέα_ς” the hoplites and the cavalry besides” X. H. 2.4.9, γέρων χωρεῖ μεθ᾽ ἑτέρου νεα_νίου an old man comes with (a second person, a young man) a young man besides Ar. Eccl. 849. Cp. “And there were also two other malefactors led with him to be put to death” St. Luke 23. 32.

[*] 1273. ἄλλος other, rest often precedes the particular thing with which it is contrasted: τά τε ἄλλα ἐτί_μησε καὶ μυ_ρίους ἔδωκε δα_ρεικούς he gave me ten thousand darics besides honouring me in other ways (lit. he both honoured me in other ways and etc.) X. A. 1.3.3, ““τῷ μὲν ἄλλῳ στρατῷ ἡσύχαζεν, ἑκατὸν δὲ πελταστὰ_ς προπέμπει” with the rest of the army he kept quiet, but sent forward a hundred peltasts” T. 4.111.

[*] 1274. ἄλλος followed by another of its own cases or by an adverb derived from itself (cp. alius aliud, one . . . one, another . . . another) does not require the second half of the statement to be expressed: ἄλλος ἄλλα λέγει one says one thing, another (says) another X. A. 2.1.15 (lit. another other things). So ἄλλοι ἄλλως, ἄλλοι ἄλλοθεν.

a. Similarly ἕτερος, as συμφορὰ_ ἑτέρα_ ἑτέρους πιέζει one calamity oppresses one, another others E. Alc. 893.

[*] 1275. After ὁ ἄλλος an adjective or a participle used substantively usually requires the article: ““τἆλλα τὰ μέγιστα” the other matters of the highest moment” P. A. 22d. Here τὰ μέγιστα is in apposition to τἆλλα (1272). οἱ ἄλλοι πάντες οἱ, τἆλλα πάντα τά sometimes omit the final article.

[*] 1276. ὁ ἄλλος often means usual, general: παρὰ τὸν ἄλλον τρόπον contrary to my usual disposition Ant. 3. β. 1.