A.T. Robertson Commentary John 11:16

"Thomas therefore, who is called Didymus, said unto his fellow-disciples, Let us also go, that we may die with him." — John 11:16 (ASV)

Didymus (Διδυμος). The word means twin. Clearly Thomas had a twin brother or sister. Applied two other times to him (20:24; 21:2). The Aramaic word for Thomas means Twin and Didymus is just the Greek equivalent of Thomas. He may even in Greek circles have been called Didymus.

His fellow disciples (τοις συνμαθηταις). Dative case and article use like "his." Only use of συνμαθητες in the N.T., rare word (in Plato).

Us also (κα ημεις). As well as Jesus, since he is bent on going.

That we may die with him (ινα αποθανωμεν μετ' αυτου). Purpose clause with ινα and the second aorist active subjunctive of αποθνησκω. Die with Jesus, Thomas means. Lazarus is already dead and they will kill Jesus (verse 8). Pessimistic courage surely.