Learn Spanish (Latin America): Si el programa falla, presiono este botón. - If the program fails, I press this button.

This is a "real conditional" sentence. When you are talking about something that is likely to happen or a general fact (If A happens, B happens), you use si followed by a verb in the present tense, and then another present tense verb for the result.

The word programa ends in "a". Why does it use el?

El programa is a masculine word. Many Spanish words that end in -ma are actually masculine. Other common examples you might remember are el problema, el sistema, and el idioma.

Why is it este botón instead of esto botón for "this button"?

Este is the masculine singular adjective for "this," used when it comes directly before a masculine noun like botón. You would only use esto if you were talking about "this" without naming the object, for example, if you just said "I press this" (presiono esto).

Could I say "si el programa falla, yo presiono este botón"?

Yes, that is perfectly fine! However, because the -o ending on presiono already clearly means "I press," the yo is usually dropped in everyday Spanish unless you want to emphasize that you are the one pressing it.