||If there were any, linguistic universals would be properties that were found in all languages (i.e. universally). One might consider questions about linguistic universals per se, that is, questions as they arise with respect to any possible language. However, it is more common to focus on such questions as they arise with respect to human languages, or human languages that are normally acquired, or acquirable, as first languages. The three main questions here are the following. First, are there any linguistic universals? Second, assuming that there are linguistic universals, what are they? Are there universals relating to grammar or syntax, for example an underlying Universal Grammar? Are their lexical universals, types of expressions, features of expressions, or constraints on expressions, found in all (human) languages? Third, if there are linguistic universals, how is this to be explained? Is it demonstrable a priori that there must be linguistic universals, or some specific range thereof, or are the universals explained e.g. by human biology or the natures of human-inhabited environments, including social environments? As the third question indicates, the issues about linguistic universals are closely connected with questions about innateness.