English Grammar | Using a comma with discourse markers   To summarize, it's clear that renewable energy sources are vital for future sustainability. [correct]   To summarize it's clear that renewable energy sources are vital for future sustainability. [incorrect]   Considering for instance, the adoption of electric vehicles. [incorrect]   Considering, for instance, the adoption of electric vehicles. [correct]   Discourse markers   Discourse markers are words or phrases that help connect ideas in a text. They are usually set apart from the rest of the text with commas.      Typically , a comma follows a phrase or adverb that introduces a sentence.    Furthermore , many individuals experience discrimination in their workplace.    Conversely , the rate of unemployment has decreased.    In conclusion , it's necessary for local councils to evaluate the expenses associated with recycling programs.    Regrettably , all the tickets were sold out.    Likewise , animals that live o...