attend
To be present at something and pay attention to it.
To attend means to be present at an event or place. When you attend school, you show up and participate in your classes. When someone attends a birthday party, a concert, or a soccer game, they go there and take part in what's happening.
The word suggests active presence and engagement. When you truly attend to something, you're giving it your focus and attention. A doctor attends to her patients by carefully listening to their symptoms and treating them. A gardener attends to his plants by watering them and checking for problems. When your teacher asks you to attend carefully to the instructions, she wants your full concentration: your mind focused on understanding and working with the material as she explains it.
You'll also hear the word in phrases like attend to your duties or attend to business, which means handling your responsibilities seriously.
An attendant is someone whose job is to be present and help others, like a flight attendant on an airplane or a museum attendant who answers visitors' questions.