Chess of the position. Weaknesses in the pawn structure, such as isolated, doubled, or backward pawns and , once created, are often permanent. Care must therefore be taken to avoid these weaknesses unless they are compensated by another valuable asset (for example, by the possibility of developing an attack). A chess opening is the group of initial moves of a game (the "opening moves"). Recognized sequences of opening moves are referred to as "openings" and have been given names such as the Ruy Lopez or Sicilian Defense. They are catalogued in reference works such as the "Encyclopaedia of Chess Openings". There
Comparison of Portuguese and Spanish in both languages, but the stress falls on different syllables: Although the vocabularies of Spanish and Portuguese are similar, the two languages differ phonologically from each other, very likely because of the stronger Celtic substratum in Portuguese. Phonetically Portuguese bears similarities to French and to Catalan while the phonetics of Spanish are more comparable to those of Sardinian and Sicilian. Portuguese has a significantly larger phonemic inventory than Spanish. This may partially explain why it is generally not very intelligible to Spanish speakers despite the lexical similarity between the two languages. One of the main differences between the Spanish and