1. "You're older than him."
* Aganan ka kenkuana a lakay. (This is the most direct translation, using the term "lakay" to emphasize seniority)
2. "You're older to him."
* Aganan ka kenkuana. (This is a simpler translation, focusing on the age difference)
3. "You're older than your brother."
* Aganan ka iti kakabsatmo a lalaki. (This specifies the relationship as brother)
4. "You're older than his brother."
* Aganan ka iti kakabsatna a lalaki. (This specifies the brother's relationship to the person being addressed)
It's important to note that Ilocano grammar is quite different from English, so a literal word-for-word translation might not be accurate. The best translation would depend on the specific context and intended meaning.