Thomas the Twin

Why was Thomas "called Twin" (John 20:24)?
θωμας (Thomas), the original word of Hebrew origin transliterated "Thomas," means "the twin," and διδυμος (Didymos), the original Greek word translated "Twin" (John 20:24), means "twin." Thomas is being identified by both the Hebrew and Greek versions of his name, and most likely was born with a twin sibling.

Why are the disciples present referred to as "the eleven" in Luke 24:33 if Thomas wasn't with them?
"The eleven" in Luke and "the twelve" in John 20:24 refer not to a headcount of those who were present in the room but to the group of disciples Jesus chose as His apostles (less Judas, the son of perdition) early in His ministry (see Judas).

How many times did the other disciples tell Thomas that they have seen the resurrected Jesus?
The tense of ελεγον (elegon), the original Greek verb translated "said" (John 20:25), indicates that they kept on saying it to him, yet he insisted, “Unless I see in His hands the scar of the nails, and put my finger into the scar of the nails, and put my hand into His side, I will not believe” (John 20:25).

When did Jesus appear to Thomas and reappear to the other disciples?
It was customary to count any part of a day when counting days, so "after eight days" (John 20:26) meant a week later - i.e., the next Sunday.

What else did Jesus' words above communicate to Thomas?
'I know what you have been saying when the others told you that I have risen from the dead.'