Why sysout won't work?

I checked the preferences settings in my Eclipse, it's all set to default with sysout option on, but when I typed sysout in eclipse, it won't automatically go into `System.out.println()`. I've checked several other related topics which mention ctrl + space. It is a shortcut for input method on my computer. I don't know if this is related to my unable to use the sysout. If not, please let me know how I can get my sysout working. If yes, please kindly let me know how I can reset 'ctrl + space' or set other shortcut for content assistant.