This question already has an answer here:
I came across the following sentence on Memrise:
Ich denke, es ist langweilig
and was confused because the verb ist does not go to end, like I thought it should.
Here is another example:
Ich glaube nicht, dass die Liga langweilig ist
Almost the same sentence, but now the verb is at the end. I trust that both sentences are correct. Is it because of dass? Or is it not so strict in modern German?