**Here are 10 examples of using the word «theory» in English:**
1. According to the Big Bang **theory**, the universe began with an incredibly dense and hot state about 13.8 billion years ago and has been expanding ever since.
2. The **theory** of evolution explains how species change over generations through natural selection and genetic variation.
3. Many people believe in the germ **theory** of disease, which states that microorganisms cause infections and illnesses.
4. Albert Einstein's general relativity **theory** revolutionized our understanding of gravity and spacetime.
5. Some scientists propose a **theory** that life on Earth may have originated from extraterrestrial sources through meteor impacts.
6. The **theory** of plate tectonics explains how the movement of tectonic plates causes earthquakes, volcanoes, and mountain ranges.
7. Freud's psychoanalytic **theory** suggests that unconscious conflicts and childhood experiences shape our personality and behavior.
8. The **theory** of relativity states that the laws of physics are not absolute and can vary depending on the observer's frame of reference.
9. Social learning **theory** proposes that individuals learn through observation, imitation, and reinforcement.
10. The **theory** of quantum mechanics describes the behavior of particles at the atomic and subatomic level and is based on the principles of uncertainty and wave-particle duality.