Students often confuse these four words due to their ortographical similarity, however it is fundamental that you can recognise the difference in order to correct include them in your written work.Por qué, formed of the preposition por and the interrogative/exclamative qué, is used to pose both direct and indirect questions and exclamatory sentence. e.g. ¿Por qué no viniste ayer a la fiesta? / No comprendo por qué te pones así. / ¡Por qué calles más bonitas pasamos!Porqué, on the other hand, is a masculine noun that is equivalent to causa, motivo and razón. We write it with an accent because it is a palabra aguda that ends in a vowel. e.g. No comprendo el porqué de tu actitud. [= la razón de tu actitud]Por que without an accent is most commonly seen in relative clauses, with the appropriate article (el, la, los, las) written prior to que. e.g. No sabemos la verdadera razón por (la) que dijo eso. Porque is used most frequently to introduce subordinate clauses that express cause - 'because'. e.g. No fui a la fiesta porque no tenía ganas.