把 bǎ as a preposition in "把" sentences, it is used before the objective to change the sturcture of the sentence. eg. 医生看好了小明的病。 The doctor cured Xiao Ming's illness. 医生把小明的病看好了。 The doctor got Xiao Ming's illness cured. 我昨天洗了衣服。I washed clothes yesterday. 我昨天把衣服洗了。I got clothes washed yesterday.

和 hé as a conjunction used between nouns or nominal constituent parts as "and", can't be used between sentences as "and". eg. 我和她都喜欢跳舞。She and I both like dancing. 你的咖啡有奶油和糖。 You coffee contains cream and sugar. as a preposition 1 with 和……一起 with...together...; 我和你一起去。I will go with you. and ....at the same time 电话和门铃一起响了。 the phone and the door bell ring at the same time. 我要和妻子去日本旅游。I will go to Japan for travel with my wife. 2 A 和 B are the same or different, or in contrary 他的论点和你的相反。 和.....一样 the same as 我和你一样，都是英语老师。 虽然我和你来自不同的国家，但是我们都会说中文。 3 to, 我想和你谈谈。I want to talk to you/have a word with you. 和你说实话，to tell you the truth

了 le 1 used after verbs, to show that something has been done or happened eg. past tense 他写了一本书。 perfect tense 电影已经开始了。 这本书我看了3 天了。I’ve read the book for 3 days. 这本书我看了一个星期。 I’ve read the book for a week. 我有20 天没见到你了：I haven’t seen you since 20 days. 我来美国已经两年多了：I’ve been in US for more than 2 years. 2 used after adjectives, to show the change in the situation or state eg. 我们来晚了。天已经黑了。这个苹果烂了。 3. Suggestion: to do or not to do: 走了，走了，别等了。 好了，不要再说了！ 4 used after the adjective "完", to express the meaning like "Gosh" eg. 完了，我忘了带钥匙！oops, I forgot to take the keys.

【了】 动词过去时态标志，完成标志。放在动词后。 【把】 宾语标志，放在宾语前。