Meaning and Usage
The verb 膨らむ (ふくらむ) primarily means "to expand," "to swell," or "to become inflated." It is often used to describe physical objects like balloons or dough that increase in size by filling with air or another substance.
Figurative Uses
Beyond physical expansion, 膨らむ is frequently used metaphorically to describe things that grow or increase in a non-physical sense, such as debts, expectations, or plans. For example, 借金が膨らむ means "debts are increasing," and 期待が膨らむ means "expectations are swelling."
Common Collocations
- 風船が膨らむ (balloon swells): describing physical inflation.
- 借金が膨らむ (debt swells): financial increase, often negative.
- 期待が膨らむ (expectations swell): emotional or mental growth.
Register and Politeness
膨らむ is a neutral verb suitable for both formal and informal contexts. It is commonly used in everyday conversation, news, and written texts.
Learner Tips
Be careful not to confuse 膨らむ with膨らます (ふくらます), which is the transitive form meaning "to inflate" or "to make something swell." 膨らむ is intransitive, so the subject itself swells or expands without an external agent.
Understanding this distinction helps avoid common mistakes in sentence construction.