Contractions and colloquial expressions are deemed inappropriate in a formal report therefore, it is not acceptable. Contractions and colloquial expressions can only be used in casual discussions and exchange of ideas but not in a formal-report making. In making a formal report, you need to use the appropriate and formal words to convey your idea and establish the credibility and authenticity of your report. Contractions and colloquial expressions in a formal report may send a negative impression to the readers or listeners making the paper less credible.
