Reading comprehension: read the passage carefully and then answer the question that follows. To know language is to be able to speak it; even a child who does not yet attend school can speak his or her language. In order to speak a language it is important to listen to it and to read a few pages in it every day. A child picks up language and learns to talk just as (s)he learns to walk. Walking and talking come naturally to a child as it grows. In our country, a child may grow up speaking more than one language, if these languages are spoken in the home and in the neighbourhood. We call this multilingualism. A child speaks a language or languages much before (s)he starts going to school. To know a language then is first of all to be able to speak it as easily and naturally as a three year old child does. Later on the child will learn to read and write in that language. In order to read and write in a language, one has to speak it. But it is possible to speak a language but not be able to read or write in it. A baby does not speak until it is nine months old but it understands a few words at six months of age. It has been listening ever since it was born, and even a little before that. So the first strategy in speaking a language is to listen. Question: To know a language one must be able to

Introduction / Context:
This question checks your ability to capture the author's main idea about what it means to truly know a language. The passage describes different skills such as listening, speaking, reading, and writing, and then gives a specific statement summarising the core requirement.

Given Data / Assumptions:

• The passage states that to know language is to be able to speak it.
• It emphasises that a child speaks a language even before going to school.
• It adds that to know a language is first of all to be able to speak it as easily and naturally as a three year old child does.
• The question asks what one must be able to do in order to know a language.
• Options mention speaking, reading, writing quickly, and singing.

Concept / Approach:
To answer this, you should identify the author's explicit definition or summary in the passage. The sentence that begins To know a language then is first of all to be able to speak it as easily and naturally as a three year old child does directly answers the question. This is more specific than a simple mention of speaking and connects knowledge of language to natural, effortless speech.

Step-by-Step Solution:
Step 1: Look for sentences starting with To know a language in the passage. Step 2: Read the full statement that explains this idea. Step 3: Note the exact condition: to be able to speak it as easily and naturally as a three year old child. Step 4: Choose the option that repeats this meaning most accurately.

Verification / Alternative check:
Although reading and writing are important, the passage clearly says that speaking comes first, and one can even speak without being able to read or write. Therefore, any option that focuses on reading well, writing quickly, or singing does not match the author's definition of knowing a language.

Why Other Options Are Wrong:

• Read it well all the time: Reading is mentioned as a later skill, not the primary definition of knowing a language.
• Write it quickly: Speed in writing is never used in the passage as a measure of language knowledge.
• Sing in the language: Singing is not discussed and is not central to language knowledge.

Common Pitfalls:
A frequent mistake is to equate knowing a language with academic skills like reading and writing, because school learning often focuses on them. However the passage highlights natural spoken fluency as the first and most basic sign of knowing a language, using the example of a three year old child.

Final Answer:
Correct option: Speak it as easily and naturally as a three year old child.