Questions & Answers about Tengo dolor de estómago hoy.
Spanish usually talks about physical sensations with tener (to have), not with ser or estar.
- Tengo dolor de estómago. – I have a stomach ache.
- Tengo frío. – I am cold.
- Tengo hambre. – I am hungry.
Using estar (estoy dolor de estómago) is incorrect in this structure. Ser is also not used for temporary physical states like this.
In Spanish, subject pronouns (yo, tú, él, etc.) are usually dropped because the verb ending already shows who the subject is.