In Russian grammar, the instrumental case helps us understand how actions happen and who is doing them. It’s especially important when we talk about people and animals. Let’s break down how to use it in simple ways:

1. How an Action is Done: Use the instrumental case to explain how something is done when talking about living things.

   • For example: "Я пишу письмо с другом."
     (I am writing a letter with a friend.)

2. Being Together: Use the instrumental case to show who you are with.

   • For example: "Я иду с сестрой в кино."
     (I am going to the movies with my sister.)

3. Talking About Jobs: Use the instrumental case to say what someone does for work.

   • For example: "Он работает врачом."
     (He works as a doctor.)

4. Time Spent Together: Use the instrumental case to say how long you are with someone.

   • For example: "Я говорю с ним долго."
     (I am talking with him for a long time.)

5. Making Comparisons: Use the instrumental case when comparing two living things.

   • For example: "Она сильнее своего брата."
     (She is stronger than her brother.)

6. After Certain Words: Some words, like "с" (with), always need the instrumental case when discussing living things.

   • For example: "Я еду с друзьями."
     (I am traveling with friends.)

7. Who Did Something: Use the instrumental case to show who did an action.

   • For example: "Эта работа выполнена учителем."
     (This work was completed by the teacher.)

By remembering these uses, students can correctly use the instrumental case when talking about people and animals in Russian.