Straightforward, obvious, simple, or basic.
words of one syllable
Simple, clear, straightforward language; blunt language.
in words of one syllable
In simple, clear, straightforward language; in blunt language.
cut and dried
Simple, straightforward, clear, or certain.
clear blue water
An obvious, unambiguous divide between the policies of two parties.
go without saying
To not need to be said or mentioned; to be obvious, apparent, clear, o…
a cigar is just a cigar
The matter is simple and straightforward.