(1) burst out可以表示：
①突然开始(做)某事。
Seeing the clown falling off the ladder, everyone suddenly burst out in laughter/burst out laughing.
看到那小丑从梯子上掉下来，大家哄堂大笑。
②(从某处)逃跑。引申作“挣脱，摆脱”解，也可用break out, bust out, crash out。
Three men burst/broke out of prison yesterday.
三名囚犯昨天越狱逃跑了。
I shall like to burst/break out of this meaningless way of life.
我想摆脱这种毫无意义的生活方式。
③突然说；打断(某人的话)。也可用burst in, break in, cut in。
“Don't hit me!” she burst out .
“别打我！”她突然说。
“But I was there!” Jim broke in/burst in/cut in .
“可我当时在那里！”吉姆打断对方的话。
④(人)长大了(衣服小了)。
The children are bursting out of their clothes so quickly now.
孩子们长得这么快，衣服都穿不下了。
(2) break into可表示：
①将某物分成(小部分、小块等)。这时，可与cut into, divide into, separate into换用。
She broke the chocolate into pieces, one for each child.
她把巧克力分成小块，一个小孩一块。
②闯进，破门而入。此时也可用burst into。
The thieves waited until it was dark enough to break/burst into the house.
这些窃贼等到天黑下来后闯进了那所房子。
The box looks as if it's been broken/burst into .
这箱子看上去好像被强行打开过。
③打扰、打断(说话)。
The children broke into the conversation with demands for attention.
孩子们打断大人说话，要求不要冷落他们。
④突然发出(笑声等)。
The boys broke into song./The boys broke forth into singing.
这些男孩突然唱起歌来。
The girls broke (forth) into laughter.
姑娘们突然大笑起来。
⑤突然开始(某种动作)。
Seeing a policeman coming, the thief broke into a run.
看见警察过来，小偷撒腿就跑。
As I grew more afraid, I broke into a cold sweat.
我越来越害怕，突然出了一身冷汗。
⑥不情愿地动用一部分(如金钱或其他物品)。这时，也可用cut into。
We shall have to break/cut into our savings to pay for the holiday.
我们将不得不动用一部分积蓄来支付假日费用。
I keep a small supply of tinned food in the bottom of the cupboard, to be broken into only in case of real need.
我在碗橱底下放了少量的罐头，只有在真正需要时才动用。
(3) break out in可表示“突然发出(笑声等)；开始出现(疹子、斑点等)；因恐惧出(冷汗)”。
The girls broke out in loud laughter.
姑娘们突然大笑起来。
When I thought that no one was coming back to save me, I broke out in a cold sweat.
当想到无人前来救我时，我一下出了一身冷汗。
(4) burst into可表示：
①匆匆进入(某处)。
The children burst into the room.
孩子们突然闯进房间里来。
②突然开始(某事)；突然进入(某种状态)。
Mary burst into song/laughter/tears.
玛丽突然唱起歌来/大笑起来/大哭起来。
The weather turned warm unexpectedly, making the trees burst into leaf.
天气意想不到地转暖了，使这些树迅速长出了树叶。
(5) bust out也可表示“突然(做某事)”。
The whole crowd bust out laughing.
整个人群突然大笑起来。
(6) crack out可表示“突然开始(大笑等)”。
Everyone at the party cracked out laughing when Jim walked in wearing his funny hat.
当吉姆戴着他那顶滑稽的帽子走进来时，晚会上每个人都大笑起来。