Grammar: B1 - ⚙️ Verbs in Depth: 🎭 Modals & 🌱 Non-Finite Verbs (Introduction) - Lesson 7: Infinitives of Purpose (I study English to get a better job.)

Grammar: Sentence Structure

B2 Lesson 7: Infinitives of Purpose

What you will learn: By the end of this lesson, you will be able to use infinitives of purpose (to, in order to, so as not to) to clearly explain the reason for an action.

Why It Matters: Being Clear and Concise

Using an infinitive of purpose is the most common way to answer the question "Why?". It connects two ideas into one smooth, fluent sentence.

Less Fluent

I went to the market. I wanted to buy some vegetables.

Clear & Fluent ✅

I went to the market to buy some vegetables.

The Grammar Rules 📖

The structure changes slightly depending on if the purpose is positive or negative.

Positive & Formal Purpose

The basic structure is Main Clause + to + verb.

• Many tourists come to Battambang to see the famous bat caves.
• He is studying hard to get a good job in the future.

For more formal writing, you can use "in order to" or "so as to".

• She exercises regularly in order to stay healthy.

Negative Purpose

To explain the purpose of *preventing* something, you must use the full phrases "in order not to" or "so as not to".

• Correct: She studied quietly in order not to disturb her roommate.
• Correct: I wrote down the address so as not to forget it.
• Incorrect: She studied quietly not to disturb her roommate.

💡 Pro Tip: Adding Emphasis

In formal writing, you can begin a sentence with the infinitive of purpose to add emphasis to the reason.

To get a good job in the future, he is studying hard.

Practice Your Grammar 🎯

Exercise 1: What's the Purpose?

Complete the sentences with the correct infinitive of purpose.

1. I went to the post office _______ a package to my family.
   to send / to mail
2. He is saving his money _______ a new motorbike.
   to buy
3. She spoke very quietly _______ wake up the sleeping baby.
   in order not to / so as not to
4. They took a tuk-tuk from their hotel _______ walk in the hot sun.
   in order not to / so as not to

Your Grammar Mission ⭐

Exercise 2: Explain Why

Answer these questions using a full sentence with an infinitive of purpose.

1. Complete this sentence: "I am learning English..."
   (Example: ...to communicate with people from other countries.)
2. Answer the question: "Why do people exercise?"
   (Example: People exercise to stay healthy and strong.)

Key Vocabulary

• Purpose (Noun) | គោលបំណង
  The reason for which something is done or created.
• Infinitive (Noun) | កិរិយាស័ព្ទដើម
  The basic form of a verb, with or without 'to' (e.g., to go, go).
• Clause (Noun) | ឃ្លា
  A group of words consisting of a subject and a verb.
• Formal (Adjective) | ជាផ្លូវការ
  Used in serious situations or with people you respect; not casual.