Learn Italian: L'applicazione sembra reattiva, ma c'è un'anomalia. - The application seems responsive, but there is an anomaly.

We know it is a personal construction because sembra has a specific grammatical subject (l'applicazione). Because it acts as a linking verb here, the adjective following it must agree with the subject in gender and number. Since applicazione is feminine singular, the adjective becomes reattiva. If it were an impersonal construction, the structure would change entirely and require the subjunctive, such as: Sembra che l'applicazione sia reattiva (It seems that the application is responsive).

Could I use pare instead of sembra here?

Yes, absolutely. Sembrare and parere are largely interchangeable in Italian. You could say L'applicazione pare reattiva. Both verbs function the exact same way in this personal construction, linking the subject directly to the descriptive adjective.

Doesn't reattiva usually mean 'reactive'? Why does the translation say 'responsive'?

While reattivo does mean 'reactive' (such as in chemical reactions or having quick reflexes), in the modern context of computing and software, it is the standard Italian translation for 'responsive'. A fast, well-functioning app or a dynamically adjusting website is described as reattiva.

Why is there an apostrophe in un'anomalia?