1. Introduction

2. Construction of consistent EFT for inflation
2.1 Truncated action for EFT
2.2 The role of Goldstone Boson
2.3 Pathology of weak coupling approximation

3. Quantum fluctuation from Goldstone modes

4. Structures from EFT

5. EFT Parameters and Fisher Forecast
5.1 Case I: M₂ ~ M̄₁ ≪ 1
5.2 Case II: M₂ > M₁

6. Summary