1.tag用作名词是“标签”的意思,转化为动词作“加标签”解,一般用于商品中,有时侧重指用线绳把图符代号标牌拴在物品上,一般无详细说明。用作及物动词,接名词或代词作宾语。
2.tag引申可作“以特殊的方式评价或描述”解,作此解时常带有强烈的感情色彩,评价的对象可以是物,但主要是指人。用作及物动词,接名词或代词作宾语,还可接以“(as+)n./adj.”充当补足语的复合宾语。可用于被动结构。
3.tag常与along, on等连用,表示“在后追随,紧跟在后”。
4.tag的过去式和过去分词均为tagged。

tag along(v.+adv.)
在后追随,紧跟在后 come along as a follower, to follow closely
▲tag along
I'll just tag along and watch you all playing.我跟在后面看着你们大伙儿玩。
If you're going to the park, do you mind if I tag along?如果你到公园去,我跟你一起去你介意吗?
We didn't invite him to go with us but he tagged along anyway.我们没有邀请他和我们一块儿去,但他还是跟来了。
Tag along with us if you like.你愿意的话就跟我们一起走吧。
The little child always tags along with her mother.那个小孩总是紧随在妈妈身后。
The baby elephant was tagging along behind its mother.小象一直紧跟在母象的后面。

tag on(v.+adv.)
1.接近,紧跟在后 keep close; follow closely
▲tag on
He tagged on behind.他紧紧跟在后面。
▲tag oneself on to sb
During the interval, a young fellow tagged himself on to the actress, and she couldn't get rid of him for the rest of the evening.幕间休息时,一个小伙子硬缠住了那位女演员,此后她整个晚上都没能甩掉他。
▲tag on to sb
The child always tags on to his elder brother.这个孩子总是跟随着他哥哥。
Don't tag on to us all the time.别老缠着我们。
2.把…附加在后面 attach as an addition
▲tag sth on to sth
The poem he tagged on to his speech seemed a bit forced.他附加在演说后的那首诗似乎有点勉强。
▲tag sth⇔on
He decided to tag on an extra paragraph at the end summarizing what he'd said.他决定在结束部分再增加一段文字,总结一下他说话的内容。

用作及物动词
▲S+～+n./pron.
The clerks tagged the merchandise for sale.店员把商品标价销售。
The porter tagged my trunks.搬运员给我的皮箱加上标签。
Tag the bottles now or we'll forget which one is which.给这些瓶子贴上标签,否则我们会记不清哪个瓶子装的是什么。
He tagged a request for money to the end of his letter.他在信的末尾添加了一个需要钱的请求。
◇ 用于be ～ed结构
There are certain packages that must be tagged as well as labelled.有些商品不仅要贴标签,还要拴标签。
All his trunks are tagged with his name and address.他所有的箱子都标上他的姓名和地址。
The pitcher was tagged with the loss of the game.人们将输球的责任归咎于该投手。
用作宾补动词
▲S+～+n./pron.+(as) n./adj.
One may tag this book traditional.人们可以称这本书为传统作品。
◇ 用于be ～ed结构
He was tagged as a quitter.他被人们称为胆小鬼。
The aged professor was tagged as a stranger man.那位年迈的老教授被称为一个奇怪的人。
Ever since she failed her exam she's been tagged as stupid.自从她考试不及格以来就被说成是一个笨蛋。
After his failure, he was tagged a failure.那次失败后,他就被认为是一个没出息的人。

tag, chase, follow, pursue, tail, trail
参见follow条。

Have you put tags on your baggage?你在自己的行李上贴上标签了吗?
The old scholar's writing is always full of tags.那位老学者的文章里总是有很多名言警句。

［同义词］ n.  label, ticket