Use single quotation marks for the inner quote if the outer quote uses double quotation marks
Use double quotation marks for the inner quote if the outer quote uses single quotation marks
Use a different punctuation style if required by the citation style you are following
Keep punctuation consistent with the quotation style you are using
Example: She said, “He told me, ‘I will be there soon.'”
Example: ‘She said, “I am ready.”‘