syllable. in words that end with a consonant, on the last syllable, with the exception of two grammatical endings: , for third-person-plural of verbs, and , for plural of nouns and adjectives or for second-person-singular of verbs. However, even though a significant number of nouns and adjectives ending with are also stressed on the penult (, , ), the great majority of nouns and adjectives ending with are stressed on their last syllable (, , , ). Preantepenultimate stress (stress on the fourth-to-last syllable) occurs rarely, only on verbs with clitic pronouns attached (e.g. 'saving them for him/her/them/you'). In addition to the many exceptions to these tendencies, there are numerous minimal pairs that contrast solely on stress such as ('sheet') and ('savannah'); ('boundary'), ('he/she limits') and ('I limited'); ('liquid'), ('I sell off') and ('he/she sold off'). The orthographic system unambiguously reflects where the stress occurs: in the absence of an accent mark, the stress falls on the last syllable unless the last letter is , , or a vowel, in which cases the stress falls on the next-to-last (penultimate) syllable. Exceptions to those rules are indicated by an acute accent mark over the vowel of the stressed syllable. (See Spanish orthography.) Speaker population Spanish is the official, or national language in 18 countries and one territory in the Americas, Spain, and Equatorial Guinea. With a population of over 410 million, Hispanophone America accounts for the vast majority of Spanish speakers, of which Mexico is the most populous Spanish-speaking country. In the European Union, Spanish is the mother tongue of 8% of the population, with an additional 7% speaking it as a second language. Additionally, Spanish is the second most spoken language in the United States and is by far the most popular foreign language among students. In 2015, it was estimated that over 50 million Americans spoke Spanish, about 41 million of whom were native speakers. With continued immigration and increased use of the language domestically in public spheres and media, the number of Spanish speakers in the United States is expected to continue growing over the forthcoming decades. Dialectal variation While being mutually intelligible, there are important variations (phonological, grammatical, and lexical) in the spoken Spanish of the various regions of Spain and throughout the Spanish-speaking areas of the Americas. The variety with the most speakers is Mexican Spanish. It is spoken by more than twenty percent of the