TAUTOLOGY

[Kasenechka]

Hi!

While my preparation for the TOEFL, in "Grammar & structure" comprehantions I faced with such an issue: Tautology. And here I have a question: why such phrases like:

Join together
Advance forvard
repeat again - are wrong,

but today, in reading comprehantion I've found this: to mix together, to cluster together

What's the difference between this phrases?

[Supper]

When you join things, you put them together, so saying join together is redundant.
Advance itself means to move forward, so say advance forward is also redundant.

to mix and to cluster, on the other hand, mean to blend things or to put things in a way so that they will become as one unite. So to mix or to cluster only means "to put" things in the same environment then help them reach a state called "together." That is why mix together, cluster together or blend together is the correct way to say.