Whether you need to add some comments to students' assignments or just want to add a little clarification to the study material, adding a text box to a PDF is a convenient way to update the document without starting from scratch.
1. Click Annotate on the toolbar;
2. Tap Text to add text;
3. Click the area you want to add the text;
4. Adujst Font / Text Alignment / Text Color / Fill Color / Border Color / Line Width / Opacity and Note if you like;
5. Right-click the texts you entered -> choose Cut / Copy / Delete text.