1. Lecture 2: Language Announcements & Review Announcements Accounts? Pair in discussion sections PAI 3.70 The Web page works www.cs.utexas.edu/users/ mckinley/305j Last Time Syllabus About me & you Fun, high paying CS jobs

2. Lecture 2: Language Today What is language? –a system for communication, comprised of a set of symbols and a set of rules, a grammar, that manipulates them. What’s a computer language? How do we communicate with a computer?

3. Lecture 2: Language Noam Chomsky Born 1928 MIT Professor 1955- present Linguist/Computer Scientist Changed how we think about language all computer languages derive from his work

4. Lecture 2: Language Language Acquisition Universal Grammars –Roger Bacon (1214-1294) “Nativist Theory” - Noam Chomsky –Language is innate –You are born with language principals –Listening to others (eg, parents) fills in your brain language template

5. Lecture 2: Language Language Acquisition “By Instruction” - Catherine Snow born 1945, McGill PhD 1971 Harvard 1980--present Psychologist Parent & peer instruction read more on language: en.wikipedia.org/wiki/Language_acquisition

6. Lecture 2: Language Language Hypotheses After about 12, sophisticated fluent language acquisition is not possible - Erick Lenneberg Since children of immigrants are fluent in new language, it must be innate not learned- Dereck Bickerton

7. Lecture 2: Language Language Vocabulary - the words in a language Grammar - the study of the classes of words, their inflections, and their functions and relations in the sentence Syntax 1.the way in which linguistic elements (words) are put together to form constituents (phrases or clauses) 2.a connected or orderly system : harmonious arrangement of parts or elements Semantics - what it means

8. Lecture 2: Language Language Modeling Universal grammar –with a limited set of rules, humans can produce an infinite variety of sentences Grammar classifications & hierarchies –Noam Chomsky Computer scientists use these formal grammars to describe and check computer languages

9. Lecture 2: Language Computer Languages High-level computer languages –what you want to read & write –examples? Assembly language (Low-level) –closer to the computer, but still human readable –some humans write this form, but YUCK! –Compiler produces this form from high-level form How hard is this translation? Machine language or object code –binary instruction representation –Compiler produces this form from assembly

10. Lecture 2: Language Discussion Computer speaks to us? What does it say? We speak to it, what can we say to it? What can a computer do? How can we express what we want the computer to do?

11. Lecture 2: Language Questions?