(1)加上，添(增)加(put sth together with sth else so as to produce a greater number，amount or size，etc)[T+n，T+n+prep(to)]：You have only to～water.你只需加点水。May I～a point or two (to the plan)? 我可不可以(在计划中)增加一两条内容?～sugar to one's tea/milk to one's coffee/water to one's whisky 在茶中加糖/咖啡中加牛奶/威士忌中加水;～more items to a list/some words to a new edition 在单子中增加一些项目/新版中增加一些词语;～a tree to a picture/an annexe to a building/a suffix to a word 在画上添加一棵树/在一建筑上加盖附属建筑/在一词尾加上后缀;～some wood to increase the fire 添劈柴以使火烧旺些;～insult to injury/fuel to the flames 凌辱交加/火上加油;That was an～ed disappointment/advantage/charm.那使人更失望/更占优势/更迷人。〖同〗include，attach，join;〖反〗remove，exclude，reduce;

(2)加，求和(join numbers or amounts together to get a total)[T+n，T+n+prep(to)，T+n+adv(together)，I]：If you～4 to 4/4 and 4 together ，you get 8.4加4/4和4相加得8。～100 to the total 在总数上加上100;～the figures together 把这些数加起来;The boy still doesn't know how to～.这男孩仍然不知如何做加法。～in one's head 心算;〖同〗total，sum up;〖反〗subtract;

(3)补充说(写)(say or write further)[T+n，T+n+prep(to)，T+that]：I have nothing to～(to my earlier statement).(对以前所说)我没什么可补充了。She explained and～ed that she was sorry.她作了解释，并说很抱歉。“And I quite agree，” he～ed.“所以我完全同意，”他补充说。

(4)增加(be or serve as an addition)[I+prep(to)]：His illness～ed to the family's troubles.他的病给他的家庭添了麻烦。The bad weather～ed to their difficulties.坏天气使他们的困难加大。The news～ed to his happiness.那消息使他更快乐。This will～to our trouble/his knowledge.这会给我们添麻烦/增加他的知识。

add in (v adv)加(倒)进(vt)：I haven't～ed in the cost of transport.我还没有把运输费用加进去。～in some lemon juice 倒进点柠檬汁;

add up (v adv)：1)累加(vt & vi)：～up the column of figures 把这行数字累加起来;The child can't even～up.这孩子甚至不会做加法。These figures would not～up right.这些数字加不对。2)合乎情理(vi)(infml)：The various facts in the case just don't～up.这案子的种种事实简直不合乎情理。

add up to (v adv prep)：1)总计达(vt)：The money he spent～ed up to ￡1000.他花掉的钱总计为1000英镑。2)意味着(vt)：The evidence～s up to a case of murder. 证据表明这是一件谋杀案。

→′additive n 添加剂;ad′dendum n 补遗，附加;(pl)附录;ad′dition n;

【辨异】add是“添加”(把……加到……中去);increase是“增加”((使)……本身数量或质量等增长);plus “相加”，且为介词，而不是动词。