Here we are going to introduce you with some Gmail keyboard shortcuts that can help you to work faster.To enable keyboard shortcuts, you have to click on Settings and then select the 'Keyboard shortcuts on' radio button.
Basic Gmail keyboard Shortcuts:
c: Compose a new message.
Tab+Enter: Send a message
j: Move cursor to the next oldest conversation
x: Selects the current conversation
Hold Shift +c to compose a message in a new window
g then i: Go to the Inbox
g then a: Go to "All mail"
g then k: Opens Tasks and switches the focus to it
k: Move cursor to a more recent conversation
n: Move cursor to the next message
o or Enter: Opens your conversation
e: Archives selected conversation
!: Marks current conversation as spam
a: Reply to all