Why is 38 written as three words but 28 is one word?

Spanish compound numbers 21-29 historically fused into single words through frequent usage (veintiocho), but numbers 31 and above retained their three-word structure (treinta y ocho) because the fusion pattern only applied to the twenties.

Is 38 degrees Celsius a fever in Spanish-speaking countries?

In all Spanish-speaking countries using Celsius, 38°C (treinta y ocho grados) is considered the threshold for fever, commonly described as 'tener fiebre' or 'tener calentura' in some Latin American countries.

How do I say 'thirty-eighth' as an ordinal?

The formal ordinal is 'trigésimo octavo,' but this form is almost never used in daily speech — Spanish speakers strongly prefer cardinal numbers for positions above tenth, saying 'el número treinta y ocho' instead.

Spanish vocabulary · Beginner

How to Say 38 in Spanish

Written by Sofia Ramirez, Lead Spanish Curriculum Editor · Reviewed May 2026

Treinta Y Ocho · noun · TRAYN-tah ee OH-choh

The number 38 is 'treinta y ocho' in Spanish, written as three separate words. Unlike numbers 21-29 which are single compound words, numbers from 31 to 99 use the structure 'tens + y + units' with spaces between each element.

Pronounced TRAYN-tah ee OH-choh with three distinct word-stress points. The 'y' conjunction is pronounced as a quick 'ee' linking the tens and units.

El paciente tiene treinta y ocho grados de temperatura.

The patient has a temperature of thirty-eight degrees.

How Native Speakers Use Treinta Y Ocho

Real example sentences across three contexts you'll actually run into.

Temperature

Tiene treinta y ocho de fiebre; necesita descansar.

She has a fever of thirty-eight; she needs to rest.

Body temperature in Celsius (fever threshold).

Shoe size

Uso talla treinta y ocho en zapatos europeos.

I wear a size thirty-eight in European shoes.

European shoe sizing system.

Address

Vivimos en la calle Roble, número treinta y ocho.

We live on Oak Street, number thirty-eight.

Giving a street address number.

Avoid These Mistakes When Using Treinta Y Ocho

Writing as one word

Incorrect: Tengo treintayocho años.

Correct: Tengo treinta y ocho años.

Unlike 21-29 which are single words, numbers 31+ must be written as separate words: 'treinta y ocho' with spaces.

Omitting y

Incorrect: Son treinta ocho personas.

Correct: Son treinta y ocho personas.

The conjunction 'y' (and) is required between the tens and units for all compound numbers from 31 to 99.

Lock in 38 Vocabulary with the Parrot Method

Why word lists alone don't stick

Memorizing a translation feels productive, but most learners forget 70% of what they studied within 48 hours. Vocabulary needs spaced repetition AND real-world exposure to transfer to long-term memory.

See Treinta Y Ocho used by native speakers

Parrot's short-form videos feature native speakers using treinta y ocho in real situations. Context-based exposure beats flashcards, you hear El paciente tiene treinta y ocho grados de temperatura. while watching someone live the moment, connecting meaning, sound, and rhythm at once.

Save, review, repeat, stay consistent

Tap any word to save it. Parrot's spaced-repetition system surfaces it right before you'd forget, no manual flashcard creation. The watch, parrot back, save, review cycle turns recognition into fluency at 2.7x the speed of traditional study.

Common Questions About 38 in Spanish

Why is 38 written as three words but 28 is one word?: Spanish compound numbers 21-29 historically fused into single words through frequent usage (veintiocho), but numbers 31 and above retained their three-word structure (treinta y ocho) because the fusion pattern only applied to the twenties.
Is 38 degrees Celsius a fever in Spanish-speaking countries?: In all Spanish-speaking countries using Celsius, 38°C (treinta y ocho grados) is considered the threshold for fever, commonly described as 'tener fiebre' or 'tener calentura' in some Latin American countries.
How do I say 'thirty-eighth' as an ordinal?: The formal ordinal is 'trigésimo octavo,' but this form is almost never used in daily speech — Spanish speakers strongly prefer cardinal numbers for positions above tenth, saying 'el número treinta y ocho' instead.