Salvador Pons Bordería is Full Professor of Spanish Linguistics at the University of Valencia, Spain. as founding member of the Val.Es.Co. Research Group, his main research interests focus on discourse markers, conversational analysis and grammaticalization studies. Óscar Loureda Lamas is Full Professor of Spanish Linguistics and Vice-President of the University of Heidelberg. He is founder of the DPKog Research Group, one of the leading groups in Experimental Pragmatics with regard to discourse markers. Contributors are: Margarita Borreguero Zuloaga, Ana Llopis Cardona, Elizabeth Closs Traugott, Ulrich Detges, Mar Garachana, David Gerards, Paul Gévaudan, Johannes Kabatek, Óscar Loureda, Piera Molinelli, Maj-Britt Mosegaard Hansen, Laura Nadal, Álvaro Octavio de Toledo, Salvador Pons Bordería, Inés Recio.