开始 - means to start (to do something) 开启 - means to open sth, to turn on some device. 例如：开始工作 - start working （开启工作 ×） 比赛开始了 - The match started. （比赛开启了 ×） 这将会是一个新的开始 - This will be a new beginning. （这将会是一个新的开启 ×） 开启电脑 - start up the computer. （开始电脑 ×） 开启开关 - turn on the switch. （开始开关 ×） 开启天窗 - open the skylight （开始天窗 ×） Sometimes they can be interchangeable, but there is a subtle difference between their meanings: 开始新的纪元 - to start a new era 开启新的纪元 - to open up a new era As for 统统 and 通通, they are basically the same. You can use whichever you like.