跟讀練習: What's an if statement? 🤔 - 通過影片學習英語口語
選擇練習模式
每種模式都會開啟全屏練習室。
92 句
如果句子過短或過長，請點選 Edit 進行調整。
1
All right guys, we are on if statements.
2
With an if statement, you do something if a condition you set is true.
3
If not, then don't do it.
4
It's as simple as that.
5
We'll ask a user what their age is.
6
If their age is greater than or equal to 18, they'll be allowed into our site.
7
If they're under 18, well, we won't let them in.
8
Let's declare variable age.
9
Int age.
10
Then we'll create a prompt.
11
standard output enter your age.
12
Standard input age.
13
Okay, this is how to write an if statement.
14
You type if, then a set of parentheses, then a set of curly braces.
15
If some condition within the parentheses is true, you perform some subset of code.
16
We are going to check if age is greater than or equal to 18.
17
Greater than or equal to is a comparison operator.
18
There's other comparison operators such as less than or equals to, less than, greater than.
19
If you need to compare if two values are equal, you use two equal signs.
20
You don't wanna say equals because then you're setting age equal to 18.
21
Equals is the assignment operator.
22
So let's check to see if age is greater than or equal to 18.
23
Then we'll print a message.
24
Standard output.
25
Welcome to the site.
26
Okay, let's Let's try this.
27
Enter your age.
28
Let's say that I'm 12.
29
Well, it doesn't do anything.
30
Since this condition evaluated to be false, we skip over this body of code.
31
If it were true, then we execute it.
32
This time my age is 21.
33
I hit enter.
34
Welcome to the site.
35
If you would rather do something else if a condition is false, you can use an else statement.
36
An else statement you will place at the end.
37
There is no condition.
38
Else, we will print standard output.
39
You are not old enough to enter.
40
Okay, let's try this again.
41
Enter your age.
42
I'll say that I'm 12.
43
You are not old enough to enter.
44
That's an if statement.
45
If some condition is true, you do something.
46
If not, you can do something else or nothing at all.
47
There are more conditions you can check by using an else if statement.
48
We can check another condition by adding else if.
49
If this condition is false, check this else if condition.
50
Let's check to see if age is less than zero.
51
That means somebody hasn't been born yet.
52
You haven't been born yet.
53
Okay, now check this out.
54
Let's say that my age is negative 10.
55
Then I hit enter.
56
You haven't been born yet.
57
Since this condition was false, we skip this section of code.
58
Then we check the else if statement.
59
Since this condition was true, we execute this body of code.
60
Then skip over the else statement.
61
Let's add one more else if statement.
62
Else if...
63
Age is greater than or equal to 100.
64
Standard.
65
Output.
66
You are too old to enter this site.
67
Okay, enter your age.
68
I am 120 years old.
69
I hit enter.
70
Welcome to the site.
71
We check these conditions one by one starting from the top.
72
We stated that our age was 120 years old.
73
Even though we were expecting to execute this body of code, we instead executed this body of code within the if statement.
74
That's because our age was technically still greater than or equal to 18.
75
So the order of your if and else if statements does matter.
76
It makes a difference.
77
If we need to execute this body of code, if somebody's age is greater than or equal to 100, well then we should probably move that to the top.
78
Then turn it into an if statement.
79
Else if age is greater than or equal to 18, we will display this message.
80
Let's try this one more time.
81
Enter your age.
82
I am 120 years old.
83
I hit enter.
84
You are too old to enter this site.
85
So yeah, that's an if statement.
86
You do something if a condition is true.
87
If not, then you don't do it.
88
If you would rather do something else, you can use an else statement.
89
If there's other conditions you would like to check before reaching the else statement, you can use an else if statement.
90
And there's really no limit to these.
91
If you would like a copy of this code, I'll post this in the comment section down below.
92
And well, yeah, those are if statements in C++.
同頻道
FOR YOU
推薦影片
B19
39 句
Basic vs. Advanced English 
Business EnglishHigh School StudentsUniversity Students
B161
16 句
Zero Conditional | English Conditional Tenses
Daily ConversationHigh School Students
B15
179 句
Using Would Have, Could Have, Should Have - English Grammar Lesson
British AccentBusiness EnglishHigh School StudentsUniversity Students
B1129 句
DOWN BAD IN DENVER - crowd work
TeensDaily ConversationHigh School Students
B11
121 句
What is range function and how to use it? How to trace for loop in python?
Daily ConversationUniversity Students
B13
137 句
What is Your Mental Age?- Test
TeensDaily ConversationHigh School Students
B14
152 句
Speak English Fearlessly with this One Question
Business EnglishDaily ConversationHigh School Students
B21
164 句
12 Important Concepts In the Age of AI Software Development
Business EnglishUniversity StudentsWorking Adults
B11
44 句
How to Improve Your English FAST! (10 Minutes!) ⭐️
Business EnglishDaily ConversationHigh School Students
B12
258 句
STOP Making These CRINGE English Mistakes
American AccentBusiness EnglishDaily ConversationHigh School Students
B23
201 句
ALL OF MATH explained in 14 minutes
Business EnglishUniversity StudentsWorking Adults
B13
79 句
If I Were You - Conditionals in English
Daily ConversationHigh School StudentsUniversity Students
本課的詞彙與口語要點
這節 B1 級別的口語課以影片“What's an if statement? 🤔”為素材。 影片中反覆出現的詞有：statement, condition, equal, enter, greater。 這段影片共有 92 個句子、733 個單詞可供跟讀。 講話部分時長為 4:53。 說話人語速自然，每分鐘約 150 個詞，接近日常對話。 92% 的單詞屬於英語最常用的 3,000 詞，詞彙容易理解。
影片中的重點詞彙
影片中最難的 10 個單詞，附發音和釋義：
| 單詞 | 發音 | 釋義 |
|---|---|---|
| execute 動詞 | /ˈɛksɪˌkjuːt/ | 處決 /處決, 處死 /處死 |
| skip 動詞 | /skɪp/ | 跳 |
| operator 名詞 | /ˈɑpəˌɹeɪtɚ/ | 話務員 /話務員, 接線員 /接線員 |
| parenthesis 名詞 | /pəˈɹɛn.θə.sɪs/ | 圓括號 /圓括號, 插入語 /插入語 |
| subset 名詞 | /ˈsʌbˌsɛt/ | 子集 |
| curly 形容詞 | /ˈkɝli/ | 捲曲的 /捲曲的 |
| evaluate 動詞 | /ɪˈvaljʊeɪt/ | 評價 /評價 |
| declare 動詞 | /dɪˈklɛɚ/ | 宣佈 |
| technically 副詞 | /ˈtɛk.nɪˌkəl.i/ | 嚴格來說 /嚴格來說 |
| assignment 名詞 | /əˈsaɪn.mənt/ | 分配, 佈置 |
值得反覆跟讀的句子
影片中簡短而完整的句子，可以直接用在日常對話裡：
- We'll ask a user what their age is.
- Then we'll create a prompt.
- Then we'll print a message.
- You haven't been born yet.
- Let's add one more else if statement.
影片中的語法
說話人最常用的結構，並附上影片中的原話：
| 結構 | 影片中的用法 |
|---|---|
| 條件句 if + 從句，will/would + 動詞 — 條件及其結果 | If they're under 18, well, we won't let · If there's other conditions you would like |
| 被動語態 be + 過去分詞 — 強調發生了什麼，而不是誰做的 | be allowed · been born |
| 現在完成時 have/has + 過去分詞 — 過去發生但與現在仍有關聯的事 | hasn't been born · haven't been born |
| 比較級 -er than / more … than — 比較兩個事物 | greater than |
需要注意的發音
說話人用了 19 次縮略和弱讀形式，例如 don't, we'll, haven't。請按聽到的簡短形式來說。
- 長單詞——注意重音位置: operator /ˈɑpəˌɹeɪtɚ/, parenthesis /pəˈɹɛn.θə.sɪs/, technically /ˈtɛk.nɪˌkəl.i/
中文母語者容易讀錯的音：
- /v/ — 不要讀成 /w/，上齒輕觸下唇: evaluate /ɪˈvaljʊeɪt/, variable [ˈvæɹ.i.ə.bl̩]
- 詞尾子音 — 要讀清楚，後面不要加母音: execute /ˈɛksɪˌkjuːt/, skip /skɪp/, parenthesis /pəˈɹɛn.θə.sɪs/, subset /ˈsʌbˌsɛt/, brace /bɹeɪs/
如何用這段影片練習
- 先完整聽一遍影片，不要開口，記下不認識的單詞。
- 先用 0.75 倍速逐句跟讀，熟練之後再回到正常速度。
- 錄下自己的聲音並與原聲對比，特別注意 execute, skip, operator 這類單詞。
什麼是跟讀法？
跟讀法 (Shadowing) 是一種有科學依據的語言學習技巧，最初開發用於專業口譯員的培訓，並由多語言者Alexander Arguelles博士普及。這個方法簡單而強大：您在聽英語母語原聲的同時立即大聲重複——就像是一個延遲1-2秒緊跟說話者的影子。與被動聽力或語法練習不同，跟讀法強迫您的大腦和口腔肌肉同時處理並模模擬實的講話模式。研究表明它能顯著提高發音準確性，語調，節奏，連讀，聽力理解和口語流利度——使其成為雅思口語備考和真實英語交流最有效的方法之一。