Identity / Classification
Copular clause
Predicate nominal
Classification
What is it? Who is who?
core
basic
Scene core
Meaning
A relation that identifies, names, classifies, or equates one participant with another role, class, or label.
How to spot it
Ask whether the sentence says that X is Y or belongs to a class.
Examples
Words
doctor|teacher|friend|problem
Phrases
my brother is a doctor|this is a mistake
Sentence
She is a doctor.
Visual guide
Basic shape
Identity/class frame: X = Y She = a doctor person = class/role Meaning: X belongs to Y
Compare shape
Same link, different marking: [She] [is] [a doctor] [She] [doctor] zero BE [She] [doctor-CASE] Marking changes; X = Y stays.
Language View
In your language
English (US default)
Presence
strong
Importance
English identity and classification commonly use 'be', often with an article before singular count nouns.
She is a doctor.
is a doctor = classification
In learning language
Arabic (Modern Standard)
Presence
strong
Difficulty
Identity and classification are often expressed as nominal sentences without present-tense copula.
أحمدُ طبيب.
Ahmad doctor.
Typical learner issue
Learners may overuse هو or miss how definiteness changes identity meanings.
Same block, different coding
Both languages use this block strongly, but they signal it differently. Focus on form changes, not only meaning.