Sign In Get Started
Prepositions after verbs

Purify by, from, with, in or of

Purify often combines with from to show what is removed and with or by to describe methods or substances used.

Quick answer

Using prepositions with purify

Use purify from or purify of to show what is removed, although of is more formal. Use purify with for the substance or tool used. Use purify by for the method. In usually introduces a place or field, not a standard complement after purify.

The filter purifies water from harmful chemicals.
The air was purified with special equipment.
The liquid is purified by heating.

Choose the pattern by meaning

These forms are not interchangeable. Choose the construction by meaning, not by which preposition appears most often.

1
purify from + substance

Removing harmful material

Use from to identify what is removed from something.

This process purifies drinking water from bacteria.
The treatment purified the soil from toxins.
2
purify of + substance

Formal expression for removal

Purify of is more formal and less common than purify from.

The system purified the air of smoke particles.
The medicine was designed to purify the blood of impurities.
3
purify with + substance/tool

Describing what is used

With introduces the material, chemical, or tool used in purification.

They purified the water with chlorine.
The laboratory purified the sample with advanced filters.
4
purify by + method

Explaining the purification method

By introduces a process or method.

The oil is purified by repeated filtration.
Water can be purified by boiling.

See the difference in context

The same subject can take different constructions because each sentence answers a different question.

Construction
Example
Meaning
purify from
The device purifies water from contaminants.
removes harmful material
purify of
The treatment purified the blood of toxins.
formal way to express removal
purify with
They purified the surface with alcohol.
shows the substance or tool used
purify by
The liquid was purified by heating.
shows the method
purify in
Scientists study how substances purify in closed systems.
in usually introduces context or location, not the normal complement

Common mistakes

Some combinations appear in real text but do not mean what learners often assume.

Using purify in as the main complement

In usually adds context or place rather than the thing removed.

✕ The filter purifies water in bacteria. ✓ The filter purifies water from bacteria.

Confusing by and with

By introduces a method; with introduces a substance or tool.

✕ The water was purified by chlorine. ✓ The water was purified with chlorine.

Omitting the object after purify from

State what is being purified and what is removed.

✕ The machine purifies from chemicals. ✓ The machine purifies water from chemicals.

Using of in very informal contexts

Purify of is grammatical but more formal than purify from.

✕ This filter purifies tap water of dirt. ✓ This filter purifies tap water from dirt.

Quick practice

Choose the expression that matches the intended meaning.

1. The system purifies drinking water ___ heavy metals.
2. The equipment purified the sample ___ ultraviolet light.
3. The liquid was purified ___ evaporation.

Check your sentence in context

Paste the complete sentence below. Linguix checks the preposition together with grammar, spelling, punctuation, and style.

Free to try · No signup required

Frequently asked questions

Is purify of old-fashioned?

It is still used, especially in formal or scientific writing, but purify from is more common in everyday English.

Can I say purified by chlorine?

With chlorine is usually more natural because chlorine is the substance used, not the method.

Does purify always need a direct object?

Usually yes. The sentence normally states what is being purified.

pack-with-in-into-for, on paint in, on, with, by or for? "park in" or "park at"? "partake in" or "partake of"? pass through, by, on, in or to? pave with, in, by, for or to? pay for, to, by, in or on? "peddle by" or "peddle to"? "peek at" or "peek into"? "peel off" or "peel for"? "pee on" or "pee in"? "peer into", "peer through" or "peer at"?

Write with confidence in Linguix

Create a free account to check complete texts, apply suggestions, and save your documents.

Create a free account