I’m happy when I spend time with my family, and I’m sad when I fail an exam.
Tom is tall; he is 1m 95 sm . Peter is short; he is only 1m 65 sm .
I’m young; I’m 26. However, my granddad is very old; he is 92.
Carlos is very strong; he goes to the gym every day. Richard is weak, he hardly ever does exercise.
David is fat; he eats a lot. Maria is thin; she needs to eat more.
She is a beautiful model, but her cousin is very ugly. Her boyfried is handsome. We are kind and always help others.But our neighbours are mean. Everyone in their group is smart/intelligent. They aren’t stupid.

Singular(1) – is

Plural(2+)  – are

Short forms
I’m
You’re
He’s
She’s
It’s
We’re
You’re
They’re

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Present-simple-with-to-be-negative