Learn Turkish: Fırtına yıkıcı olmakla kalmayıp bütün bahçeyi mahvetti. - The storm wasn't just destructive, it ruined the whole garden.

This is a fixed grammar structure combining olmak (to be) + -la (with) + kalma (not staying) + -yıp (connecting converb). Literally, it means 'not remaining with being [destructive],' which is the natural way to express 'not only being' or 'wasn't just'.

Why do we need the -la suffix on the infinitive olmak?

In this pattern, the verb kalmak (to stay or remain) partners with the instrumental/comitative case -lA (with). You are expressing that the storm did 'not stay WITH' the first action, so the preceding infinitive always takes -lA.

What is the exact role of the -yıp ending at the end of kalmayıp?

The -(y)Ip suffix is a converb that connects two verbs done by the same subject, acting like 'and' to avoid starting a new sentence. Here, it fluidly links the negative state of 'not staying' directly to the final action of ruining the garden.

Why is the object written as bahçeyi rather than just bahçe?

The verb mahvetmek (to ruin) is transitive and takes a direct object. Because the sentence refers to a specific, entire garden (bütün bahçe), it requires the definite accusative suffix -(y)i, making it bahçeyi.