My dear X,
Regarding the attached: Let us set aside for the moment the fact that your heroine, a woman of deep perception and understanding, fails to grasp that when she alights from a train in Wales and is spoken to by a Welshman, he is likely speaking Welsh–not gobbledygook–to her. Let us also ignore, for the present, that the only thing she quotes as intelligible from the gentleman’s speech is, in point of fact, rendered as gobbledygook. Let us instead focus on the verb “presume.”
The job of a writer is to know, to the best of their ability, the meanings and connotations of the words they choose to use in their writing. It appears that you are using “presume” with its most common meaning here (“to suppose to be true without proof”), but let us reason together: your heroine and her friend board a train for Wales; Cardiff is announced as the final stop; the two travelers disembark from the train in Cardiff; a man approaches them and speaks a language other than English. How much more proof does one need that the Welsh in Wales speak Welsh?
It may be that you mean “assume” here, but I cannot presume to assume that. You must have a good reason for using “presume”: perhaps the subtle connotations of the word communicate something about our heroine? I have corrected the MS to clarify this point.