Frail vs Weak

When to use each in English, with meaning, register, and examples.

Frail

Top 3,000 (common)

Weak

Top 1,000 (very common) A2

Most common: Weak

	Frail	Weak
Pronunciation	🇬🇧 //freɪl// 🇺🇸 //freɪl//	🇬🇧 /["/wiːk/"]/ 🇺🇸 /["/wiːk/"]/
Meaning	Weak or thin, easily damaged.	Not strong or powerful.
Example	The frail man struggled to carry the heavy box.	She felt weak after running the marathon.
Register	Neutral	Neutral
How common	Top 3,000 (common)	Top 1,000 (very common)
CEFR level	-	A2
Collocations	frail health, frail body, frail figure	appear, be, feel, extremely, fairly, very, at, from, in, weak at the knees, appear, be, feel, extremely, fairly, very, at, from, in, weak at the knees, appear, be, feel, extremely, fairly, very, at, from, in, weak at the knees
Antonyms	strong, robust, sturdy	strong, powerful, robust
Common mistakes	Confused with 'fragile' - both mean weak but in different contexts., Using 'frailed' as a past tense; correct form is 'frail'.	Confused with 'week' (the time period), Using 'weak' to describe intelligence instead of 'not intelligent', Overusing 'weak' to describe emotions, which can be seen as negative or stigmatizing
Usage notes	Used to describe physical weakness or delicacy. Avoid when referring to strong, healthy subjects.	Used to describe physical strength, emotional resilience, or ineffective arguments. Avoid using it in formal academic contexts to describe theories or ideas.

See it in real clips

The Sopranos › S1 E1

Is caged by frail And fragile bars

Frail

shepherds the weak through the valley of darkness,

House Of Dragons › S1 E1

You're weak, viserys.

Succession › S1 E1

I hear it played weak. Conflict-averse.

shepherds the weak through the valley of darkness,

House Of Dragons › S1 E1

You're weak, viserys.

Weak

Frequently asked questions: Frail vs Weak

What's the difference between Frail and Weak?

Frail: Weak or thin, easily damaged. Weak: Not strong or powerful.

Which is more common: Frail and Weak?

Weak is the most common in everyday English.

Can you show an example of each?

Frail: The frail man struggled to carry the heavy box. Weak: She felt weak after running the marathon.

Can I use Frail and Weak interchangeably?

Not always. Frail and Weak are related and overlap in some contexts, but they differ in register, how common they are, and usage, so swapping one for another can change the meaning or tone. Check the differences above before substituting.