In a normative aspect of contemporary Korean language, the quotation postpositions and the quotation marks are used without discrimination in both spoken language and written language.
The Quotation is to draw a linguistic form whether its object is to be expressed to an inner state or an outer. There is, however, a tendency that the speakers, who use the quotation, do not show it clearly whether the quoted sentence is a direct narration or a indirect one.
The problems, being related to the Korean quotation usage, are pointed out as follows:
In spoken language 1) It is necessary to understand that there is a distinct difference between the usage of '라고' and '하고', the quotation postpositions. 2) There is a tendency that '라고' – using in direct quotation – is used at indirect quotation. '라고' has a function to stress prior quoted phrase as like the small quotation mark – being used at written language.
In written language 1) It is necessary to recognize that there is a distinct difference between the usage of '라고' and '하고', the quotation postpositions as the same case of spoken language. 2) There is a tendency that '고', which is a quotation postposition being used in the indirect quotation, is replaced by '라고'. If the above tendency is admitted in written language, the discernment between a direct quotation and an indirect will be ambiguous, though there is a tendency to use the above case in spoken language. 3) There is a tendency that the period has not been put in the quoted sentence within a direct quotation mark. 4) The large quotation mark, which is the direct quotation mark, is used without making a distinction from the small quotation mark.
In my thoughts, the above problems are caused from the ambiguous understanding on the definition of quotation usage (direct and indirect quotation usage).
When these problems in the quotation usage of Korean language are settled, more effective use of Korean language will be realized in practical aspect.