Present: Irregular 'IR' Verbs (1)
Spanish: Cambridge International GCSE, topic 8.1.15
Stem Changing IR Verbs (E → IE)
In present tense Spanish, some IR verbs change when conjugated. The 'e' in the infinitive becomes 'ie'. This does NOT happen in the 'nosotros' and 'vosotros' forms. Derivatives of these verbs follow the same pattern.

Stem changes (E → IE)
- When conjugated, these IR verbs change from their infinitive form.
- The 'e' in the infinitive changes to 'ie' when conjugated.
- E.g. Sentir (to feel) becomes 'siento' (I feel).
- E.g. Siento, sientes, siente, sentimos, sentís, sienten.

Preferir - to prefer
- Prefiero - I prefer.
- Prefieres - you prefer.
- Prefiere - he/she prefers / you prefer (formal).
- Preferimos - we prefer.
- Preferís - you prefer (plural).
- Prefieren - they prefer / you prefer (formal plural).

Sugerir - to suggest
- Sugiero - I suggest.
- Sugieres - you suggest.
- Sugiere - he/she suggests / you suggest (formal).
- Sugerimos - we suggest.
- Sugerís - you suggest (plural).
- Sugieren - they suggest / you suggest (formal plural).

Mentir - to lie
- Miento - I lie.
- Mientes - you lie.
- Miente - he/she lies / you lie (formal).
- Mentimos - we lie.
- Mentís - you lie (plural).
- Mienten - they lie / you lie (formal plural).

Advertir - to warn
- Advierto - I warn.
- Adviertes - you warn.
- Advierte - he/she warns / you warn (formal).
- Advertimos - we warn.
- Advertís - you warn (plural).
- Advierten - they warn / you warn (formal plural).

Sentir - to feel
- Siento - I feel.
- Sientes - you feel.
- Siente - he/she feels / you feel (formal).
- Sentimos - we feel.
- Sentís - you feel (plural).
- Sienten - they feel / you feel (formal plural).
Test yourself on Present: Irregular 'IR' Verbs (1)
How do you say 'they warn' in the present tense in Spanish?