Articulation: Difficulty producing sounds clearly. "Wabbit" for "rabbit." Common in younger children; most resolve naturally. If persisting past Year 1, worth investigating.
Fluency: Stuttering or cluttered speech. Affects confidence and social interaction.
Language: Difficulty understanding or expressing ideas. A child might understand simple instructions but struggle with multi-step directions or complex sentences.
Social communication: Difficulty using language in social contexts. Taking turns in conversation, interpreting non-verbal cues, understanding jokes or sarcasm.