文中共有10处语言错误，每句中最多有两处。错误涉及一个单词的增加，修改或删除。
增加：在缺词处加一个漏字符号（^），并在其下面写出该加的词。
删除：把多余的词用斜线（/）划掉。
修改：在错的词下划一横线，并在该词下面写出改正后的词。
注意：1.每处错误及其修改均仅限一词；
2.只允许修改10处，多者（从第11处起）不计分。
Last Sunday I am about to leave the Green Lake Park when I met a foreign visitor whose seemed to be lost. I tried to help him but I found we had difficulty in understand each other because of my poor English. Just at that moment, tall young lady came to our help. He spoke very good English. With her help, the foreign visitor finally found the way but I learned some English as well. Before he left, the foreigner thanked to us for our kindness. I was very exciting that day. This experience have made me realize that English is real useful and worth learning. I will work hard at it from now on.am--was
网友回答
(答案→)am--was
解析：短文讲述的是作者帮助一个外国人，但英语不好，双方交流遇到了困难。这时，过来一个女士，帮助了那个外国人找到了路。
【小题1】考查时态。根据Last Sunday可知，是过去时，故把am改成was。
【小题2】考查定语从句。定语从句seemed to be lost缺少主语，先行词指人，whose作定语，故把whose改成who/that。
【小题3】have difficulty in doing sth做某事有困难，故把understand改成understanding。
【小题4】考查冠词。一个年轻的女士，lady可数，故在tall前加a。
【小题5】考查人称代词。根据a tall young lady可知，应该用she来指代lady。故把He改成She。
【小题6】考查并列连词。found the way和I learned some English是并列关系，故把but改成and。
【小题7】thank sb for sth/doing sth因某事而感谢某人，故去掉to。
【小题8】修饰人，用ed结尾的形容词，ing结尾的形容词修饰物，这里修饰I，故把exciting改成excited。
【小题9】experience是单数，故谓语也要用单数，故把have改成has。
【小题10】修饰形容词useful应该用副词，故把real改成really。