Irregular verb pattern
Spelling-change verbs: -uir
Verbs ending in -uir (but not -guir or -quir) insert a y between the stem and any ending that does not begin with i — giving forms like construyo, construyes.
The pattern rule
The -uir ending requires a y to be inserted before o, e, or a — wherever i would not naturally appear. This affects the present tense (except nosotros/vosotros), the preterite third person, and the present subjunctive.
Example: construir (to build / to construct) — Present
Irregular forms are highlighted in red. Regular forms for comparison are shown in grey where they differ.
| Pronoun | Actual form | Regular would be |
|---|---|---|
| yo | construyo* | construo |
| tú | construyes* | construes |
| él/ella | construye* | construe |
| nosotros | construimos | ✓ |
| vosotros | construís | ✓ |
| ellos/ellas | construyen* | construen |
Frequently asked questions
What are -uir spelling-change verbs in Spanish?
Verbs ending in -uir (like construir, incluir, and huir) insert a y before endings that begin with o, e, or a. In the present tense: construyo, construyes, construye, construimos, construís, construyen.
Why do -uir verbs insert a y?
When two vowels meet in a Spanish verb form, a y is conventionally inserted to avoid an unusual vowel cluster and to clarify pronunciation. The i in -uir becomes a consonantal y before another vowel.
All 11 -uir verbs verbs — ordered by frequency
Sorted by how commonly each verb appears in everyday Spanish. Start with rank #1 and work down.
Other irregular verb patterns
Practise these verbs with spaced repetition to actually remember them.