Student or Learner
As we know, there four types of sentence in English: simple, compound, complex, and compound complex.
But, what the type of sentences that introduce a quote?
"They must be very strange," she thought.
Remember - if you don't use correct capitalisation, punctuation and spacing, anything you write will be incorrect.
To be honest, I don't know.
Well, it cannot be simple because there are two subjects, each has a predicate, nor can it be compound because 'she thought' is not complete. Reported speech sentence is complex; it contains an embedded noun clause, but this sentence is direct speech. Obviously, the sentence is not compound-complex.