What it is: The core “building blocks” of English (levels, sentence parts, basic grammar ideas). What it’s for: Learn faster, avoid gaps, and choose the right materials. Example: If you know your level (A2/B1), you can pick the right texts and listening.

• CEFR Levels (A1–C2)
• Parts of Speech
• Sentence Basics
• Common Mistakes

• *foundation* /faʊnˈdeɪʃən/: nền tảng
• *building block* /ˈbɪldɪŋ blɒk/: “viên gạch” nền (thứ cơ bản để xây lên)
• *material* /məˈtɪəriəl/: tài liệu