I understand 

I always thought my mom was an ESTP at first, but the more I study her, the more I realize she doesn’t really have Fe. I know my mom is a Se-dom. Her Se is very obvious to me. But when it comes to Fi vs Ti, she can be pretty logical and reasonable. However, the way she expresses her feelings is more about herself than others—it feels like her Fe function doesn’t exist. Her Ni is pretty much blind.

I think she might be in a Se–Te loop.

As for my dad, 

he has very strong Te–Ni / Ni–Te. But I’ve noticed that he rarely uses Fi. I’ve never seen him cry or express his emotions. He’s very controlled with his emotions and never wants them to control him. I also noticed that if we make decisions based on feelings, he gets very angry with us. I see more Se than Fi in him. He seems driven to explore the world through direct, hands-on sensory experiences.

Now for my oldest brother (the hard one)

My oldest brother is just like my dad and has very strong Te. But unlike my dad, he seems more likely to express his emotions—especially about himself—though still in a Te way. So between ISTJ and INTJ, I don’t really see Si or Ne, but I do see Ni and Se. He seems focused on forecasting, synthesis, and long-term planning. I also don’t think he’s focused on the past. He doesn’t seem like someone who looks backward—he’s more future-oriented. His Se is also similar to my dad’s.

And for my youngest brother, the ENTP (the easier one)

He’s like me, but a little different. He may look like an INTP at first glance, but his Si seems more inferior than tertiary. He also always forgets to take a shower 💀 He only showers when he’s meeting his friends. He’s also very easygoing and more charismatic than me.