A free original bilingual lesson on selected English-letter series skills for RRB Group D reasoning. Distinguish term position from alphabet position, count letters strictly between two positions, and track fixed shifts, changing gaps, alternating subsequences and two-letter blocks. Wraparound is used only when the question explicitly permits it. Six worked cases, including a retrieval example, two unscored completion pauses, an analogy, a quick reference and five explained practice questions support careful rule checking. Every assessed series states its rule family or permitted menu; a finite list alone does not prove a unique continuation. This covers selected topic skills, not every possible series type or the full reasoning syllabus.