4. Family Members & "是" (To Be)

### New Vocabulary
| Character | Pinyin | Literal Character Meaning | English Usage |
|-----------|---------|----------|--------|
| 是 | shì | be | am/is/are |
| 弟弟 | dìdi | younger + younger | younger brother |
| 哥哥 | gēge | older + older | older brother |
| 谁 | shéi | who | who |
| 绿 | lǜ | green | green |
| 吕 | lǚ | (surname) | surname Lü |

### Possessive Phrases with Family Members
| Chinese | Pinyin | Character-by-Character | English Usage |
|---------|---------|----------|-----------|
| 我妈妈的 | wǒ māma de | I + mother + mother + possessive | my mom's |
| 我的妈妈 | wǒ de māma | I + possessive + mother + mother | my mom |
| 他的妈妈 | tā de māma | he + possessive + mother + mother | his mom |
| 她的爸爸 | tā de bàba | she + possessive + father + father | her dad |
| 我们的妈妈 | wǒmen de māma | I + plural + possessive + mother + mother | our mom |
| 他们的妈妈 | tāmen de māma | he + plural + possessive + mother + mother | their mom |

### Important Sentence Patterns
| Chinese | Pinyin | Character-by-Character | English Usage |
|---------|---------|----------|--------|
| 他是我的弟弟 | tā shì wǒ de dìdi | he + be + I + possessive + younger + younger | He is my younger brother |
| 我是哥哥 | wǒ shì gēge | I + be + older + older | I am the older brother |
| 我是Jack | wǒ shì Jack | I + be + Jack | I am Jack |
| 他是谁？| tā shì shéi? | he + be + who | Who is he? |
| 他们是谁？| tāmen shì shéi? | he + plural + be + who | Who are they? |

### Pronunciation Notes
#### J, Q, X with ü Sound
| Character | Pinyin | Notes |
|-----------|---------|--------|
| 绿 | lǜ | Uses ü sound |
| 吕 | lǚ | Uses ü sound |
- The ü sound is written as 'u' after j, q, x
- The dots are only written in other cases (like in 吕 lǚ)

### Grammar Points
1. 是 (shì) Usage:
   - Links subject with predicates
   - Used for identification
   - Cannot be used alone like English "yes"

2. Possession Patterns:
   - Both Person + family member + 的 and Person + 的 + family member are correct
   - 们 (men) indicates plural
   - 的 (de) indicates possession

### Looking Ahead
Next concept: 认识 (rèn + shi) = recognize + know → to know/recognize someone

### Common Pattern Notes
- Family terms are doubled (弟弟, 哥哥) with second character in neutral tone
- Possessive marker 的 comes after the owner
- Plural marker 们 comes after the pronoun
- Question word 谁 (shéi) comes at the same position as the answer would be