Ⅰ. pleasant 为形容词, “令人愉快的” “令人舒适的” 主要指使人心满意足,将快乐给予他人的性格、活动氛围、状态或场合，也可用于事物。如
① She has a pleasant voice. 她的声音悦耳。
② The weather there is not very pleasant. 那儿的天气不太宜人。
Ⅱ. pleased 为形容词，“感到高兴”，相当于 glad 或 happy,后面可接不定式、at doing, with sth 或 that 从句。
① We are very pleased to see you here. 我们很高兴在这儿见到你。
② I am pleased that they have dedided to come. 我很高兴他们决定来。
③ He was pleased with my progress.他对我的进步感到满意。
Ⅲ. pleasing “令人喜欢的;令人愉快的”主语一般是物。如①She has got a pleasing voice.. 她的声音很悦耳。
Ⅳ. Pleasure 是名词，大多用于客套语中。如：
① I have had the pleasure of meeting your father before. 我以前有幸见过令尊。
② --Will you lend me a hand? --With pleasure. 请你帮一下忙好吗? 好的。
Ⅴ. please 是及物动词，常用于祈使句语气，意为“请”
Please give me a cup of tea. 请给我一杯茶。
口语中，Yes, please! 好的，谢谢!对应 No, thanks.不用了，谢谢!