"Do you speak English, Mara?"
Translation:DIvI' Hol Dajatlh'a', mara?
Yes; both of those are errors.
DIvI' Hol should have a space, and "do you speak" should be Dajatlh'a' here since the verb has an object.
bIjatlh'a'? is "Do you speak?" when there is no object (the prefix bI- indicates that the subject is "you [one person]" and there is no object while Da- indicates that the subject is "you [one person]" and the object is one of "him, her, it, them" -- here, the singular noun "English").
And finally, "understand" is yaj, not jatlh.
But congratulations for getting the I versus l bit right!
You used lowercase L and both of them should be uppercase i. The Duolingo font makes it difficult to distinguish, but if you look carefully, you will see a small curl at the bottom of the l (L) that isn't on the I (i).
This is mentioned in the Tips & Notes. If you have not been reading the Tips & Notes, I would like to ask that you review those so we don’t have to continuously repeat the information that we have explained there. If you have read them and still have a question, please be specific in your question so we can figure out where the confusion is.
If you are doing the course on iOS or Android, you cannot currently access the Tips & Notes through the app. To access the Tips & Notes, you will have to access the course using a web browser at https://www.duolingo.com/, either from your mobile device or from a computer. When you click on a Skill, it will expand to reveal a Start button and a light bulb. If you click on the light bulb it will reveal the Tips & Notes and give you a detailed explanation of the grammar that is introduced in that Skill. If you have questions after reading the Tips & Notes for any Skills, then please return to the forum to ask your questions, explaining what you didn’t understand or what seems contradictory to you.
In the word DIvI' you are using lowercase L when you should be using uppercase i.
It can be very difficult to see the difference. When on the Duolingo pages, if you look carefully at the bottom of the letter, you can see a small curl at the bottom of the l that is absent from the bottom of the I.
You can also tell that the letters in DIvI' should be uppercase i, because otherwise there are no vowels. Klingon must have a vowel in every syllable. Every consonant must have at least one vowel next to it. The letter following D must be a vowel and the letter preceding ' must be a vowel.