Generally speaking, the difference is this:

一般來(lái)講，這兩個(gè)詞的區(qū)別如下：

“affect” is a verb meaning to have an influence on, to cause a change in something (often negative)，

“affect(影響)”，作為動(dòng)詞使用，指的是對(duì)某物施加影響，或?qū)е履澄锏母淖?常用作被動(dòng)語(yǔ)態(tài));

“effect” is a noun meaning a result。

“effect(影響)”，作為名詞使用，指的是一種結(jié)果。

So, for example: If an area is affected by flooding, the effect can be devastating。

例如：如果一個(gè)地區(qū)遭受洪災(zāi)，那么，這種影響是毀滅性的的。

There are also less common uses of the words:

下面為大家介紹一下這兩個(gè)詞不常見(jiàn)的用法：

Affect

Affect (影響)

“affect” as a verb meaning to simulate, put on a false show。

“affect”作為動(dòng)詞使用，意思為假裝，偽裝。

I couldn’t believe it! At the meeting he affected total ignorance of the whole plan。

我真不敢相信!他在會(huì)上竟然裝作一點(diǎn)也不知道這整個(gè)計(jì)劃。

Although he’s British he affects a very convincing American accent。

雖然他是英國(guó)人，但是裝出了一口地道的美國(guó)腔。

“affect” is also used as a noun, meaning a feeling or emotion, mainly in the context of psychology。

“affect”也可作為名詞使用，表示一種感覺(jué)或情緒，主要描寫(xiě)某種心理。

Effect

Effect (影響)

“effect” can also be used as a verb, meaning to cause to occur, to bring into existence, execute (it often collocates with the word “change”)。

“effect”也可以作為動(dòng)詞使用，意思是導(dǎo)致某事的發(fā)生;引致某物的出現(xiàn);實(shí)現(xiàn)(通常與“change(改變)”搭配使用)。

The changes effected by the new legislation led to a comprehensive revision of our employment policies。

新的立法所造成的改變使我們就業(yè)政策得到了全方面修訂。

“in effect” is an idiom that means in essence, to all purposes。

“in effect”作為俗語(yǔ)，意思是實(shí)際上，事實(shí)上。

The policy is, in effect, a tax cut for banks。

事實(shí)上，該政策是對(duì)銀行的一次減稅。

We should also note that there are some trade measures that are protectionist in effect, and have strong links with competition policy。

我們也應(yīng)注意到，一些貿(mào)易措施實(shí)際上就是貿(mào)易保護(hù)。這些政策和競(jìng)爭(zhēng)政策有緊密的聯(lián)系。

Rules, legislation, agreements etc. can be said to come into effect or take effect when they start operating。

規(guī)則，立法，協(xié)定，等，表示“開(kāi)始實(shí)施”時(shí)，可以用“come into effect”與“take effect”來(lái)表示。

The ban was agreed by international treaty in 2010, but did not come into effect until 2012.

這項(xiàng)禁令于2010年通過(guò)國(guó)際談判達(dá)成一致，但是知道2012年才正式生效。

The changes took effect without any serious disruption to manufacturing processes。

這些改變奏效了，生產(chǎn)過(guò)程沒(méi)有任何嚴(yán)重的中斷現(xiàn)象。

“personal effects” means private belongings。

“personal effects”指的是私人物品。

He came to the house yesterday to pick up some of his personal effects。

昨天，他來(lái)的家里，取走了一些他的私人物品。

Comparison of “affect” and “effect” as verbs

比較：“affect”與“effect”作為動(dòng)詞使用

The changes to the regulations will affect savings。

= The changes will probably reduce savings。

政策的改變將影響儲(chǔ)蓄。

=政策的改變很可能降低儲(chǔ)蓄數(shù)額。

The changes to the regulations will effect savings。

= The changes will lead to new savings being made。

政策的改變將對(duì)儲(chǔ)蓄產(chǎn)生影響。

= 政策的改變會(huì)刺激新的儲(chǔ)蓄。