When you have to give an instruction, you use the Imperative. The Imperative form is made by using the bare Infinitive (the Infinitive without to). However the bare Imperative may be too strong. To tone down the effect of the Imperative, you can use "politeness" words, such as please, or rephrase in the indicative with an auxiliary verb such as would. Be careful! Use your dictionary! Do the project! Do your homework! Say the alphabet! Repeat after me! Make up your story! Finish your work! Get ready! Follow the instruction! Do the task! Take your seat! Read! Write! Go to the board! Look at the board! Be quiet! Raise your hand! Answer the question! Think! Close your book! Open your book! Clean the board! Do the test! Ask the question! Listen to me! Check your work! Work in pairs!