Speech、 lecture、 address 、talk、sermon這五個詞用來做名詞時，都是指講話、發言，但在用法上有具體的區別。
1.speech指正式的演說、講話、發言（指公開或私下場合的講話均可）。
Several people made speeches at the wedding.
有幾個人在婚禮上講了話。
He made the announcement in a speech on television.
他在一次電視講話中發表了這一聲明。
to give/make/deliver a speech on human rights
就人權問題發表演講
His speech made a strong impression on the audience.
他的演說給聽眾留下了深刻的印象。
The audience reacted readily to his speech.
聽眾對他的演說立即作出反應。
2.lecture通常指大學裡的講座、講課、演講。
Neither the subject nor the title of this lecture is of my own choice.
這次講演的主題與題目都不是我自己選定的。
They are listening to the lecture with avid attention.
他們聚精會神地聽講演。
a lecture on the Roman army關於羅馬軍隊的講座
Mary attended a series of lectures on Jane Austen.
瑪麗去聽了關於簡奧斯汀的系列講座。
The professor in his lecture went beyond the capacity of his audience.
這位教授的講課超過了聽眾的接受能力。
3.address指正式的、公開的演說、演講。（當speech是正式、公開演講時可以與address替換）
public address公開演說 inaugural address就職演說
a televised presidential address總統的電視演講
He gave an address at the wedding.他在婚禮上做了演講。
Howard gave the valedictory address at high school graduation.
霍華德在中學畢業典禮上作了告別演講。
In his inaugural address, the President appealed for unity.
總統在他的就職演說中呼籲國家統一。
4.talk指相當不正式的報告、談話、演講。
She gave an interesting talk on her visit to China.
她做了個關於她在中國訪問的有趣報告。
He was too distressed to give a talk.他傷心得講不出話來。
I had to have a heart-to-heart talk with her.
我得推心置腹地和她談一談。
I suppose you could give a talk instead of her.
我想你可以代她作個報告。
Mr Wang gave us a talk yesterday.
王先生昨天給我們作了個報告。
5.sermon[s:mn]指布道、講道(一種關於道德或宗教話題的談話，通常由宗教領袖在禮拜期間進行)
In church I listen to sermon. 在教堂做禮拜時，我聽講道。
This is the end of Peter's sermon. 這是彼德的布道的結尾。
You gave a great sermon. 你做了一個很好的祈禱。
I like giving the Sunday sermon. 我喜愛做禮拜天的布道。
His sermon awoke me to a sense of sin.
他的講道使我意識到自己的罪惡。
Father gave me a sermon on table manners.
父親就餐桌禮儀問題對我作了一番說教。