Sign In Get Started
Prepositions after adjectives

Obsolete in or obsolete by

Obsolete in and obsolete by are both used, but they express different ideas.

Quick answer

Use obsolete in for fields and obsolete by for time

Use obsolete in to show the context or field where something is outdated. Use obsolete by with a time expression to mean outdated before or at that time.

The technology is obsolete in modern hospitals.
Many devices became obsolete by the 1990s.
The term is obsolete in current legal writing.

Choose the pattern by meaning

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

1
obsolete in + field/context

Outdated within a particular area

Use in for industries, systems, or situations where something is no longer used.

Fax machines are largely obsolete in many offices.
The rule is obsolete in modern education.
2
obsolete by + time

Outdated before a certain point

Use by with dates or periods in time.

The format was obsolete by 2005.
These methods became obsolete by the end of the century.

See the difference in context

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

Construction
Example
Meaning
obsolete in
The device is obsolete in most laboratories.
Shows the field or context where it is outdated.
obsolete by
The software was obsolete by 2010.
Shows the time by which it became outdated.
obsolete for
The system is obsolete for modern use.
Possible in some contexts, focusing on suitability.
obsolete to
The phrase obsolete to engineers sounds unnatural.
Not a standard pattern with obsolete.

Common mistakes

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

Using by for context

By normally introduces time, not a field.

✕ The method is obsolete by medicine. ✓ The method is obsolete in medicine.

Using in for a deadline

Use by with a point in time.

✕ The software was obsolete in 2015. ✓ The software was obsolete by 2015.

Using to after obsolete

To is not a natural complement after obsolete.

✕ This tool is obsolete to engineers. ✓ This tool is obsolete in engineering.

Quick practice

Choose the expression that matches the intended meaning.

1. The equipment became obsolete ___ the late 1980s.
2. Cash payments are becoming obsolete ___ some industries.
3. Which sentence is standard?

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

What does obsolete in mean?

It refers to the context or field where something is outdated.

When do we use obsolete by?

Use it with a time expression such as a year or deadline.

Is obsolete to correct?

It is not a standard pattern after obsolete.

obedient-to-unto-in-by, of "objective in" or "objective about"? "obligatory for" or "obligatory on"? "oblivious to" or "oblivious of"? observable in, by, from, to or on? obsessed with, by, about, in or over? obsessive about, in, over, with or to? "obtainable in" or "obtainable from"? "obvious to", "obvious from" or "obvious in"? odd to, for, about, in or on? offensive to, in, against, on or about? official with, in, for, on or at?

Write with confidence in Linguix

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

Create a free account