weak in + subject
Limited ability in an area
Use in with academic subjects or broad areas.
He is weak in chemistry.
Weak in, on, at, for, and from
Weak often combines with in or at for skills and subjects. Weak from describes a physical cause. Weak on is used for limited knowledge, while weak for can mean having a liking for something.
Quick answer
Which preposition goes with weak?
Use weak in for subjects or areas, weak at for skills, weak on for knowledge of a topic, weak from for physical causes, and weak for when someone has a fondness for something.
She is weak in mathematics.
I'm weak at remembering names.
He felt weak from the illness.
She is weak for dark chocolate.
I'm weak at remembering names.
He felt weak from the illness.
She is weak for dark chocolate.
Choose the pattern by meaning
These forms are not interchangeable. Choose the construction by meaning, not by which preposition appears most often.
weak at + skill
Poor performance in a skill
Use at for activities or abilities.
I'm weak at public speaking.
weak on + topic
Lacking knowledge about something
On often refers to limited information or understanding.
The report is weak on detail.
weak from + cause
Physically affected by something
Use from for the cause of physical weakness.
She was weak from lack of sleep.
weak for + thing liked
Having a special liking
Weak for can mean unable to resist something enjoyable.
He's weak for vintage cars.
See the difference in context
The same subject can take different constructions because each sentence answers a different question.
Construction
Example
Meaning
weak in
She is weak in science.
not good in a subject or area
weak at
He is weak at chess.
not skilled at an activity
weak on
The article is weak on evidence.
lacking detail or knowledge
weak for
I'm weak for fresh pastries.
have a strong liking for something
weak from
She felt weak from dehydration.
physically weakened by a cause
Common mistakes
Some combinations appear in real text but do not mean what learners often assume.
Using weak at with school subjects
In is usually preferred for subjects.
✕ She is weak at biology. ✓ She is weak in biology.Confusing weak on and weak in
Weak on often refers to detail or knowledge, not general ability.
✕ He is weak on mathematics. ✓ He is weak in mathematics.Using weak from for skills
From describes a physical cause, not ability.
✕ I'm weak from grammar. ✓ I'm weak in grammar.Quick practice
Choose the expression that matches the intended meaning.
1. He is weak ___ foreign languages.
2. The proposal is weak ___ practical details.
3. After the fever, she felt weak ___ dehydration.
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 is the difference between weak in and weak at?
Weak in is common for subjects and areas of knowledge, while weak at is used for skills or activities.
Can weak for mean attraction?
Yes. It can mean having a soft spot or strong liking for something.
Is weak on negative?
Usually yes. It suggests something lacks strength, detail, or knowledge in a specific area.
Related preposition guides
Write with confidence in Linguix
Create a free account to check complete texts, apply suggestions, and save your documents.
