Read this short conversation:
Cò ris a tha e coltach?
What’s he like?
A bheil e àrd agus eireachdail?
Is he tall and handsome?
Tha. Tha e àrd ceart gu leòr, tha casan fada air, agus tha gàirdeanan làidir air cuideachd.
He is. He’s tall, right enough, he has long legs, and strong arms as well.
Ach na can sin ris, no bidh ceann mòr aige!
But don’t say that to him, or he’ll get big–headed [lit. will have a big head]
In the conversation above, we saw:
Tha casan fada air
He has long legs
Bidh ceann mòr aige
He will have a big head
With the preposition aig, ceann mòr might traditionally mean ‘big–headed’, rather than a physically large head, which would typically use air.
Tha ceann mòr oirre
She has a large head
but
Tha ceann mòr aice
She is big–headed
Tha beul mòr orm
I have a large mouth
but
Tha beul mòr agam
I am big–mouthed
Cha sheas càirdeas air a leth–chois
Friendship isn’t just one–way [lit. Friendship won’t stand on one leg]