FORMAL LANGUAGE & AUTOMATA THEORY

This page collects 138 formal language & automata theory questions taken from 5 BEU semester 4 papers, 2021 to 2025 — about 28 questions in a typical paper. They are sorted into the 5 modules of the syllabus, so you can revise a topic across every year at once instead of working through papers one at a time. 62 of them have a worked solution.

What these papers actually ask

Module 1: Introduction & Regular Languages is the heaviest module in this archive at 43% of every question recorded, and it has come up in all 5 papers. Together with Module 2: Context-Free Languages (CFL) and PDA, the two account for 73% of the archive.

4 modules have appeared in all 5 papers — Module 1: Introduction & Regular Languages, Module 2: Context-Free Languages (CFL) and PDA, Module 4: Turing Machines (TM), Module 5: Undecidability. A module that turns up every year is a safer use of revision time than one with the same question count concentrated in a single paper.

How the marks are split

Questions in this archive carry 5 different mark values. The most common is the 7-mark question, with 79 of them recorded — worth knowing before you decide how much depth to practise at.