Mexican Spanish. The relationship between Mexican Spanish and Spanish in Spain can be explained like the one between British and American English.
The difference between Mexican Spanish and Spansh spoken in Spain is similar to how the English language has evolved between England and the United States. Spanish was brought as the language of Spanish conquistadores when Spain imposed its reign in America and in the case of Mexico lasted more than 300 years. It should also be noted that the Spanish spoken today in Mexico is not a homogenous language since indigenous influences have impacted the language greatly. For example, the Spanish spoken in the Yucatan is different in both pronunciation and vocabulary thanks to the influence of Maya language. Other differences that can be found within the country can heard along the border with Guatemala where speakers voseo (use the pronoun vos) influenced by Mexico´s Central American. Today, Mexican Spanish is also the accepted Spanish dialect in the United States with the exception of certain areas where Cuban, Dominican or Puerto Rican Spanish prevails.
Mexican Spanish is noted for its "sing-song" quality which is a trait left behind from the Maya, Nahuatl and Zapotec languages. This means that in tonality plays an important role in spoken communication along with the lengthening of vowel sounds and the strengthening of consonant sounds. There sounds employed in Mexican Spanish that aren't very common in Castilian Spanish like affricate consonants (for example /tl/ and /tz/) which can be found in words like chipotle or quetzal. There are also fricative consonants ([ʃ] and [x]) that are used primarily with words with indigenous origins but can also be heard in Castilian like Xavier ([ʃ] and Mexico ([x]).
The use of the second person plural pronoun (informal) vosotros is not used in Mexico where the formal pronoun ustedes is used exclusively. Another interesting difference between Mexican and Castilian Spanish is the widespread use of the diminutive even when there is no physical difference to point out. This is accomplished by using substituting the final vowel on words that end with one with –ito or –ita (papa ---> papito or mamá ---> mamita). The diminutive is also formed by adding –cito/a or –ecita to the end of words depending on how the word is constructed. Other forms of the diminutive that you can find are: -illo/a,-ico/a, -ucho/a, -ín/a, -uelo/a, -ete/a and -uco/a. But be careful when using these last diminutives since some can be considered to be derogatory! Even though diminutives are also used in Castilian Spanish, their usage is more widespread in Mexican Spanish as well as across the social spectrum and generally implies affection.
Another feature that differentiates Mexican form Castilian Spanish is the use of por instead of durante to indicate a time span. In Mexico you would likely to hear something like Hay problemas cuando un polítco va a la carcel por diez años por robar while in Spain you hear "…durante diez años…" There are also more complex grammatical differences but to the speaker you will immediately notice the differences in vocabulary, which is probably the greatest difference that attracts the attention of Spanish speakers. Some words that are typically Mexican are Güey (dude), Güero (caucasion person), Pinche (kitchen helper or a more vulgar verb), Popote (drinking straw) and Chavo (kid).
Another noticeable difference is the slower evolution of words in Mexican Spanish with respect to Castilian. This can be seen in words like anteojos/gafas (eyeglasses), carro/coche (car), boleto/billete (ticket), alberca/piscina (pool) and ¿mande?/¿dime? (pardon?). There are also expressions that are used in Mexico that are no longer used in Spain like se me hace (me parece or I think) or ¿qué tanto…? (¿Cuánto…? or how much/many). The origin of these archaisms is not entirely clear and there have been numerous studies as to how they have come about. There are theories that are based on the idea that change is faster from the center outwards (Spain to America) than if it begins on the periphery (Mexico). Another idea is that the Spanish that reached America was Andalusian and Canarian in origin, which is very similar in use and pronunciation to Mexican Spanish, which has since evolved along with the rest of Castilian Spanish while Mexican Spanish has retained these older characteristics. Whatever the reason for this particularity, it is an interesting difference for the Spanish speaker.
For people who hear Mexican Spanish they will hear an accent that is very similar to that spoken in the Canary Islands of Spain but certain vocabulary and structures are clearly Mexican. This language variation is what is heard across Mexico and is the accepted Spanish in most of the United States totaling 104 million speakers in Mexico and a large percentage of the 35 million Spanish speakers in the U.S.