Learn Dutch: Zij laat haar nagels rood lakken. - She is having her nails painted red.

This is the causative use of the verb laten. It means you arrange for someone else to do something for you, similar to "having something done" or "getting something done" in English. Here, Zij laat (she is having) combines with the infinitive lakken (to paint) to mean she is getting someone else to paint her nails.

Why is lakken placed at the very end of the sentence?

When you use laten to say you are having something done, it behaves just like a modal verb (such as willen or kunnen). The conjugated verb (laat) goes in the second position, and the main action verb (lakken) is pushed to the very end of the sentence as a bare infinitive.

Why is the word for red just rood and not rode?

In this sentence, rood is describing the result of the action (how they are painted), so it acts as an adverb. In Dutch, adverbs never get an extra -e at the end. If it were placed directly in front of the noun, it would be rode nagels (red nails), but here it stands on its own to describe the painting process.

Why is the verb lakken used here instead of verven for "painted"?