TTS Verbalization Guide & Specifications for es-MX

Product: es-MX
Release Date: October 2026
TTS Engine version: 3.4.0

Introduction

This document describes how specific series of strings are read by the TTS Engine for the ES language in the MX domain. Example outputs are in Spanish (Mexican Spanish). The readings are the engine's current output for the version above: when a reading is not what is wanted, this document still shows what the engine does.

Convention: every example table includes a Lexis voice output column. Any new row appears marked with 🆕. Missing support is shown as "unsupported". Numeric ranges use [a-b] (for example, [1-99] means any number from 1 to 99).

Readings are shown in lower case with punctuation as the engine returns it. Two markers appear in the readings: [pause] is a 0.025 s pause the Lexis voice puts between groups of digits, and [pause 0.2 s] is a fixed pause of 0.2 s.

Numbers

Integers

Format	Example input	Lexis
`[1-9][0-9]`	`25`	veinticinco
`[1-9][0-9]…[0-9]`	`159`	ciento cincuenta y nueve
`100`	`100`	cien
`10[1-9]`	`101`	ciento uno
`<dash>[1-9]…[0-9]`	`-58`	menos cincuenta y ocho
`[1-9][0-9]…[0-9][0-9] (>999)`	`2824`	dos mil ochocientos veinticuatro
`[1-9][0-9]{3}`	`1500`	mil quinientos
`[1-9][0-9]{0,2}<comma>[0-9]{3}`	`2,824`	dos mil ochocientos veinticuatro
`1000000`	`1,000,000`	un millón
`2000000`	`2,000,000`	dos millones
`1000000000`	`1,000,000,000`	mil millones

Allowed thousands delimiter: comma only; a space reads as two number groups. Max supported value: 999,999,999,999, read as "novecientos noventa y nueve mil novecientos noventa y nueve millones novecientos noventa y nueve mil novecientos noventa y nueve". Beyond that, digits are spelled one by one.

Ordinal numbers

Format	Example input	Lexis
`[1-9]…[0-9]{º}`	`1º` 🆕	primero
`[1-9]…[0-9]{ª}`	`1ª` 🆕	primera
`[1-9]…[0-9]{º}`	`21º` 🆕	vigésimo primero

Decimals

Decimal separator: dot. Digits after the dot are spelled individually ("2.4527" is "dos punto cuatro cinco dos siete", "-25.78" is "menos veinticinco punto siete ocho").

Format	Example input	Lexis
`[1-9]…[0-9]<dot>[0-9]…[0-9]`	`2.4527`	dos punto cuatro cinco dos siete
`<dash>[1-9]…[0-9]<dot>[0-9]…[0-9]`	`-25.78`	menos veinticinco punto siete ocho

Fractions and units

Format	Example input	Lexis
`[1-99]<slash>[1-99]`	`13/16`	trece dieciséisavos
`[1-99]<slash>[1-99]`	`45/2`	cuarenta y cinco medios
`[1-99]<slash>[1-99]`	`37/4`	treinta y siete cuartos

A fraction that complies with the date format, thus [1-31]<slash>[1-12], is read as a date if no supported unit is provided. Dates are day first, so "5/12" is read as "cinco de diciembre". With a unit it is a fraction ("5/12 km" is "cinco doceavos kilómetro"). Fractions such as 3/4 and 1/2 without a unit are therefore read as dates ("tres de abril", "primero de febrero").

Format	Example input	Lexis
`{vulgar fraction} <unit>`	`½ taza`	½ taza
`[1-99]/[1-99] <unit>`	`3/4 mi`	tres cuartos milla
`[1-31]<slash>[1-12] <unit>`	`5/12 km`	cinco doceavos kilómetro

A vulgar fraction such as ½ is not converted: the text passes through unchanged.

Digit-by-digit spelling

The dash notation can be used to spell the digit sequence digit by digit. For Lexis, the digits are read in groups of three, with a short pause ([pause], 0.025 s) between the groups. The comma is placed where the input has a space.

Example input	Lexis
`4-2-1-4 2-3-4 7-5-3`	cuatro dos uno [pause] cuatro, dos tres [pause] cuatro, siete cinco [pause] tres

Note: this notation can be used for digit sequences with more than 2 digits. Otherwise it will be verbalized as an interval. E.g. "2-3" is "dos a tres".

16-digit card numbers

Example input	Lexis
`5-8-9-6 4-2-6-5 1-2-3-4 7-4-6-8`	cinco ocho nueve [pause] seis, cuatro dos [pause] seis cinco, uno [pause] dos tres cuatro, [pause] siete cuatro seis [pause] ocho
`5-8-9-6-4-2-6-5 1-2-3-4-7-4-6-8`	cinco ocho nueve [pause] seis cuatro dos [pause] seis cinco, uno [pause] dos tres cuatro [pause] siete cuatro seis [pause] ocho

Counter examples

The numbers in between the dashes are read as integers and the dash is pronounced as "guion" if the dash is used more than once.
If only one dash is used, then the digit sequence is handled as an interval.
If no dash is used, the numbers are read as integers.

Example input	Lexis
`4532-1234-5678-9012` 🆕	cuatro mil quinientos treinta y dos guion mil doscientos treinta y cuatro guion cinco mil seiscientos setenta y ocho guion nueve mil doce
`4532 1234 5678 9012`	cuatro mil quinientos treinta y dos mil doscientos treinta y cuatro cinco mil seiscientos setenta y ocho nueve mil doce
`4532-1234-5678` 🆕	cuatro mil quinientos treinta y dos guion mil doscientos treinta y cuatro guion cinco mil seiscientos setenta y ocho
`4532-1234`	cuatro mil quinientos treinta y dos a mil doscientos treinta y cuatro

Telephone numbers

Format	Example input	Lexis
`([0-9]{2}) [0-9]{4}-[0-9]{4}`	`(55) 1234-5678`	( cincuenta y cinco ) mil doscientos treinta y cuatro a cinco mil seiscientos setenta y ocho
`[0-9]{2} [0-9]{4} [0-9]{4}`	`55 1234 5678` 🆕	cinco cinco, uno dos tres cuatro, cinco seis siete ocho
`+[0-9]{2} [0-9]{2} [0-9]{4} [0-9]{4}`	`+52 55 1234 5678` 🆕	más cincuenta y dos, cinco cinco, uno dos tres cuatro, cinco seis siete ocho

The country code is read as a number ("+52" is "más cincuenta y dos").

Combination of numbers and words

Format	Example input	Lexis
`[0-9]…[0-9]<dash>{word}`	`16-bit`	dieciséis bit
`{word}<dash>[0-9]…[0-9]`	`COVID-19`	covid diecinueve

A space around a dash between a number and a word verbalizes the dash as the word "guion" (e.g. "16 - bit" becomes "dieciséis guion bit"). A spaced dash between two words is read as a pause (see Dashed words).

Ratio and intervals

Format	Example input	Lexis
`[0-9]…[0-9]<colon>[0-9]…[0-9]`	`16:9`	dieciséis a nueve
`[0-9]…[0-9]<dash>[0-9]…[0-9]`	`16-9`	dieciséis a nueve
`[0-9]…[0-9]<dash>[0-9]…[0-9] {word}`	`3-5 días`	tres a cinco días

If the ratio values overlap with the time format, the time will be announced. E.g. "24:00" is verbalized as "veinticuatro horas" while "25:00" is "veinticinco a cero".

Percentage

Example input	Lexis
`15%`	quince por ciento
`2.5%`	dos punto cinco por ciento

Time

Format	Example input	Lexis
`[00-24]<colon>[00-59]<colon>[00-59]`	`12:11:01`	doce horas once minutos y un segundo
`[00-24]<colon>[00-59]`	`23:15`	veintitrés y quince
`[00-24]<colon>00`	`24:00`	veinticuatro horas
`12<colon>00`	`12:00` 🆕	mediodía
`00<colon>00`	`00:00`	medianoche
`[1-12] {PM,AM}`	`2 PM`	dos de la tarde
`[01-12]<colon>[00-59] {PM,AM}`	`02:20 PM`	dos y veinte de la tarde

Note: PM is read "de la tarde" ("1 PM" is "una de la tarde", "2 PM" is "dos de la tarde").

Date

Format	Example input	Lexis
`[2-31] de {month} de [0-9]{4}`	`14 de mayo de 2022`	catorce de mayo de dos mil veintidós
`1 de {month} de [0-9]{4}`	`1 de junio de 2020`	uno de junio de dos mil veinte
`[00-31]/[00-12]/[0-9][0-9]`	`31/12/19`	treinta y uno de diciembre de diecinueve
`[00-31].[00-12].[0-9]{4}`	`27.05.2021`	veintisiete de mayo de dos mil veintiuno
`[0-9]{4}-[00-12]-[00-31]`	`2022-11-02`	dos de noviembre de dos mil veintidós
`[1-31] de {month}`	`21 de octubre`	veintiuno de octubre
`[1-31]/[1-12]`	`23/5`	veintitrés de mayo
`[1-31]/[1-12]`	`5/12` 🆕	cinco de diciembre

Note: The day 1 is read "uno" in a full date; other days are cardinal numbers. Dates are day first, so "5/12" is the 5th of December (en-US reads May 12th). Dates and months are masculine, so 21 is "veintiuno" and 31 is "treinta y uno". A two-digit year is read as a number ("diecinueve"); a full year is read as one number ("dos mil veintidós"), without "y".

Units

Format	Example input	Lexis
`{amount}{unit}`	`2.5GB`	dos punto cinco gigabytes
`{amount}<space>{unit}`	`1.5 GB`	uno punto cinco gigabytes
`{amount}{unit}/{unit}`	`1500MB/s`	mil quinientos megabytes por segundo
`{amount}<space>{unit}/{unit}`	`1400 MB/s`	mil cuatrocientos megabytes por segundo

Supported unit abbreviations

Each reading shows the singular / the plural form: the unit is read after "1" and after "2". The readings come from the Spanish unit table of the input processor tests.

Abbreviation	Lexis
`mm`	milímetro / milímetros
`cm`	centímetro / centímetros
`m`	metro / metros
`km`	kilómetro / kilómetros
`Km`	kilómetro / kilómetros
`m²`	metro cuadrado / metros cuadrados
`m2`	metro cuadrado / metros cuadrados
`m³`	metro cúbico / metros cubicos
`m3`	metro cúbico / metros cubicos
`"`	"
`in`	pulgada / pulgadas
`'`	'
`ft`	pie / pies
`yd`	patio / yardas
`mi`	milla / millas
`mph`	milla por hora / millas por hora
`MPH`	milla por hora / millas por hora
`h`	hora / horas
`hr`	hora / horas
`min`	minuto / minutos
`mins`	minuto / minutos
`s`	segundo / segundos
`g`	gramo / gramos
`gm`	gramo / gramos
`kg`	kilogramo / kilogramos
`Kg`	kilogramo / kilogramos
`oz`	onza / onzas
`lb`	libra / libras
`lbs`	libra / libras
`ml`	mililitro / mililitros
`mL`	mililitro / mililitros
`l`	litro / litros
`L`	litro / litros
`gal`	galón / galones
`cup`	cup
`Hz`	hercios
`hz`	hercios
`kHz`	kilohercio
`MHz`	megahercio
`GHz`	gigahercios
`W`	dobleú
`kW`	kilovatio / kilovatios
`MW`	megavatio / megavatios
`GW`	gigavatio / gigavatios
`V`	voltio / voltios
`mA`	miliamperio / miliamperios
`A`	amperio / amperios
`dB`	decibel / decibelios
`kb`	kilobit / kilobits
`mb`	megabit / megabits
`gb`	gigabit / gigabits
`tb`	terabit / terabits
`pb`	petabit / petabits
`kB`	kilobyte / kilobytes
`MB`	megabyte / megabytes
`GB`	gigabyte / gigabytes
`TB`	terabyte / terabytes
`PB`	petabyte / petabytes
`bps`	bit por segundo / bits por segundo
`Kbps`	kilobit por segundo / kilobits por segundo
`Mbps`	megabit por segundo / megabits por segundo
`Gbps`	gigabit por segundo / gigabits por segundo
`Tbps`	terabit por segundo / terabits por segundo
`kBps`	kilobyte por segundo / kilobytes por segundo
`MBps`	megabyte por segundo / megabytes por segundo
`GBps`	gigabyte por segundo / gigabytes por segundo
`TBps`	terabyte por segundo / terabytes por segundo
`PBps`	petabyte por segundo / petabytes por segundo
`°C`	grado celsius / grados celsius
`°c`	grado celsius / grados celsius
`°F`	grado farenheit / grados fahrenheit
`°f`	grado farenheit / grados fahrenheit

Note: Short abbreviations that are also words or letters (in, min, h, m, A, s) are read as units only when they follow a number; "in" after a number is "pulgadas" ("5 in the box" is "cinco pulgadas the box").

Words

Abbreviations and spelling

Lexis passes words in capital letters through unchanged and the Lexis model reads them (e.g. ABC, JOHN). Dotted capital abbreviations keep their dots (e.g. B.C.).

Format	Example input	Lexis
`[A-Z]…[A-Z]`	`ABC`	abc
`[A-Z]…[A-Z]`	`JOHN`	john
`[A-Z]<dot>[A-Z]<dot>`	`B.C.`	b. c
`[A-Z]&[A-Z]`	`I&D`	i & d

Between capital letters, "&" is passed through. Between words, "&" is read as "y".

A single letter is read by its letter name: V is "ve", W is "doble u".

Common abbreviations

Example input	Lexis
`Prof.`	profesor
`Profa.`	profa
`Dr.`	doctor
`Dra.`	doctora
`Sr.`	señor
`Sra.`	señora
`etc.`	etcétera

Dashed words

Example input	Lexis
`teórico-práctico`	teórico-práctico
`e-mail`	e-mail
`Mérida - Cancún`	mérida [pause 0.2 s] cancún
`Mérida-Cancún`	mérida-cancún

URLs and e-mails

URLs

Format	Example input	Lexis
`(www)<dot>{word}<dot>{domain}`	`www.google.com`	doble u doble u doble u, punto google, punto com
`http(s)://{word}<dot>{domain}`	`https://google.com` 🆕	hache te te pe ése, dos puntos, doble diagonal google, punto com
`http(s)://www<dot>{word}<dot>{domain}`	`https://www.google.com` 🆕	hache te te pe ése, dos puntos, doble diagonal doble u doble u doble u, punto google, punto com
`(http(s)://)(www)<dot>{word}<dot>{domain}<slash>{sequence}`	`https://www.google.com/news=123` 🆕	hache te te pe ése, dos puntos, doble diagonal doble u doble u doble u, punto google, punto com, diagonal éne e dobleú ése, signo igual uno dos tres
`(http(s)://)(www)<dot>{non-word}<dot>{domain}`	`www.123.com` 🆕	doble u doble u doble u, punto uno dos tres, punto com

E-mails

Format	Example input	Lexis
`{word}@{word}<dot>{domain}`	`info@omilia.com` 🆕	i é n e é f e o, arroba omilia, punto com

Currency

Format	Example input	Lexis
`{symbol}{amount}`	`$25.10` 🆕	veinticinco pesos con diez centavos
`{symbol}{amount}`	`US$25.10`	us $ veinticinco punto uno
`{amount}{symbol}`	`25.10€` 🆕	veinticinco euros con diez céntimos
`{amount} {code}`	`25 USD` 🆕	veinticinco dólares
`{amount} {quantity} {code}`	`1.3 millones USD` 🆕	uno punto tres millones de dólares
`{symbol}{amount} {quantity}`	`$1.3 millones` 🆕	uno punto tres millones de pesos

Note: after "millón/millones" the noun is introduced by "de" ("uno punto tres millones de pesos"). In es-MX the symbol "$" is the peso; the dollar is written USD, and US$ is not expanded.

Currency codes and symbols

Each reading shows the singular / the plural form. The subdivision is read after "con" when the amount has decimals ("1.01" and "2.50").

Code	Lexis	Subdivision
`USD` 🆕	dólar / dólares	centavo / centavos
`EUR` 🆕	euro / euros	céntimo / céntimos
`GBP` 🆕	libra esterlina / libras esterlinas	penique / peniques
`AUD` 🆕	dólar australiano / dólares australianos	centavo / centavos
`CAD` 🆕	dólar canadiense / dólares canadienses	centavo / centavos
`JPY`	yen japonés / yenes japonéses	none: `1.50 JPY` reads uno punto cinco yen japonés
`MXN` 🆕	peso mexicano / pesos mexicanos	centavo / centavos

Symbol	Lexis
`$` 🆕	peso / pesos
`€`	euro / euros
`£`	libra / libras
`¥` 🆕	yen japonés / yenes japonéses
`US$`	unsupported: `US$1` reads us $ uno

Punctuation and character processing

Supported characters

Char	Description	Used as/in	Lexis
`.`	period	sentence end / decimal separator	✅
`,`	comma	sentence break / thousands separator	✅
`-`	dash	number group / minus sign	✅
`@`	at sign	email address	✅
`%`	percent	percentage value, in URLs	✅
`&`	ampersand	"y" (between capital letters it is passed through)	✅
`$ € £ ¥`	currency signs	part of currency	✅
`=`	equal sign	in URLs	✅
`;`	semicolon	in URLs	✅
`? !`	question mark, exclamation mark	sentence end (see intonation)	✅
`¿`	inverted question mark	sentence start, passed on as a token	✅
`¡`	inverted exclamation mark	sentence start, dropped	✅
`: / ( )`	colon, slash, brackets	time, ratio, URLs, fractions, dates, phone numbers	✅
`° ² ³ " '`	degree, superscripts, quotes	units	✅
`º ª`	ordinal indicators	ordinal numbers	✅

The slash is read "diagonal". Other symbols are read by name: \ "barra invertida", ^ "circunflejo", _ "guion bajo", + "más", # "numeral", $ "signo de peso", * "asterisco" and ~ "virgulilla". Outside times, ratios and URLs a colon or semicolon is replaced by a full stop, and brackets are passed on unchanged. The vulgar fraction ½ is not converted.

Any other character has no reading of its own: the processor passes it on unchanged (for example quotation marks and ©, ®, ™, §, ×, ÷, ±).

Punctuation intonation

Char	Lexis effect
`.`	falling intonation
`?`	rising intonation for yes/no questions
`,`	falling intonation
`!`	a lone exclamation mark is rewritten as a full stop (falling intonation)
space / dash	short pause (a spaced dash is a fixed pause of 0.2 s)
no punctuation at the end of a sentence	a period is added automatically