How can I tell local vegetables from fruit in Sri Lanka, and which fruits should I choose to eat fresh?

The green, bumpy item was identified as karavila, described as a bitter cucumber.

The small green item with fine spines was tentatively identified as spiny gourd.

The green banana in the purchase was identified as a cooking banana.

The tangled long pods in the second photo were identified as long beans.

The vegetable in the third photo was tentatively identified as patola and described as a type of cucumber; the identification was uncertain.

The lighter-colored vegetable was identified as white cucumber, called pipinna.

Pineapple, papaya, mango and yellow bananas were recommended for a fruit purchase; the reply described them as available almost everywhere and almost all the time.