Learn Turkish: Sistemin hata algılaması durumunda kırmızı alarm çalar. - In case the system detects an error, the red alarm goes off.

This structure links the subject and the action using a genitive-possessive pair. The subject sistem takes the genitive suffix to become sistemin. The verb algılamak turns into a verbal noun with -ma and takes the possessive suffix -sı to match the system. Finally, durumunda acts as a postposition meaning 'in the situation of', creating the literal meaning 'in the situation of the system's detecting an error'.

Why is hata used in its bare form instead of taking the accusative case as hatayı?

Because the system is detecting any general error, not a specific one. Leaving hata without the accusative marker shows it is indefinite, meaning 'an error' rather than 'the error'. If the system were looking for a previously mentioned, specific error, you would use hatayı algılaması.

Could we use halinde instead of durumunda here?

Yes, they are completely interchangeable in this grammar pattern. Both translate to 'in case of' or 'in the event of'. Durumunda comes from the Turkish word for 'situation', while halinde comes from a word meaning 'state' or 'condition'. Both are frequently used in formal, technical, or legal contexts.

Why does the verb use the aorist tense in çalar rather than the present continuous çalıyor?