I'm Tired
Use this when you mean 'I'm sleepy' and want to go to sleep. It literally means 'I have sleep'.
A stronger way to say you're tired, meaning 'I'm exhausted' or 'I'm worn out'.
Similar to 'agotado', this means 'I'm spent' or 'I'm beat'. It implies you have no energy left.
I worked all day. I'm very tired.
It's 11 at night and I'm very sleepy.
After the exercise class, I'm exhausted.
Do you want to go out? Not today. I'm spent.
'Estoy cansado/a' is the standard, universal phrase understood everywhere. 'Tengo sueño' for 'I'm sleepy' is also universal.
The standard phrases are the same. A common colloquialism for 'exhausted' is 'Estoy hecho/a polvo', literally 'I'm made of dust'.
In very informal, colloquial situations, people say 'Estoy mamado/a'. Be careful, as this can also mean 'I'm fed up'.
A common informal expression for being exhausted is 'Estoy fusilado/a', which literally means 'I've been shot by a firing squad'.
Using 'Soy cansado' instead of 'Estoy cansado'. — Tiredness is a temporary state or condition, not a permanent characteristic. For states and conditions, Spanish uses the verb 'estar', not 'ser'. CORRECT: 'Estoy cansado.' WRONG: 'Soy cansado.'
Forgetting to change the ending for gender. — Adjectives in Spanish must match the gender of the person they describe. If you are female, you must use the feminine form 'cansada'. CORRECT (for a woman): 'Estoy cansada.' WRONG: 'Estoy cansado.'
Confusing 'cansado' (tired) with 'sueño' (sleepy). — While related, they are different. 'Estoy cansado' means you are physically or mentally weary. 'Tengo sueño' means you feel the need to sleep. If you want to go to bed, the most precise phrase is 'Tengo sueño'.