When it comes to some repetitive/repetitious (words / excuses) in an argument

Question

Let's imagine you are arguing with someone pursuant to an old matter after a short time gap. Some new events make you feel that you will probably hear some new excuses/words from the person you are arguing with. But again he starts talking about the same old words and just repeats the excuses he/she had made before! What would you say here as a disapproval?

— These are all repetitive words/excuses.
— These are all repetitious words/excuses.

Also, I wonder if it would be possible to say:

• Your words / excuses have become repetitive to me.
  
• Your words / excuses have become repetitious to me.
  

Based on dictionaries, they both work semantically, but I guess they are not the ways a native would say the same thing.

Repetitive:

• Involvingdoing or saying the same thing several times, especially in a way that is boring:
  
• A repetitive job/task.
  

Repetitious:

• Filled with unnecessary and boring things expressed or happening in the same way many times:
  
• The movie got a little repetitious after the third car chase.

Answer 1

Both "repetitive" and "repetitious" stem from the same root. Both are common. One is somewhat newer, although both are so old that they're part of the standard English lexicon. From the etymology dictionary:

repetitive (adj): 1805, from Latin repetit-, past participle stem of repetere "do or say again" (see repeat (v.)) + -ive. repetitiveness.

repetitious (adj): "employing repetition," often with suggestions of tiresomeness, 1670s, from Latin repetit-, past participle stem of repetere "do or say again" (see repeat (v.)) + -ous.

"Repetitious" includes the slight nuance of "becoming tiresome or annoying", but you can imply the same thing with "repetitive" without much additional context, e.g. a "repetitive stress injury".

Either is fine in the context of your statement:

Your argument is getting repetitive.

Your argument is getting repetitious.

Or use the verb:

You keep repeating the same argument.

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Side note: Try checking the etymology dictionary as well as the others. It may give you some additional clues about the differences (or lack thereof) between similar words.