You can call attention to specific areas of text in a PDF using the Highlight Text Tool in Adobe Reader 9. However, you can use this tool only in PDFs where commenting has been enabled. According to Adobe, “PDFs in a review workflow typically include commenting rights.“ With the Highlight Text Tool, making certain pieces of text stand out is a simple process.
Open the PDF in Adobe Reader 9.
Click the “Tools” menu, highlight “Commenting & Markup” and select “Highlight Text Tool.”
Click next to the text you want to highlight, and drag the tool over the text. When you release the button, the highlighting appears. To highlight a rectangular area of text, hold the “Ctrl” key in Windows or the “Option” key in Mac, and click and drag over the area.