"Is it a language?"
The verb suffix -'a' is attached to a verb to indicate that the sentences is not a statement, but rather a yes/no question. So there is no word which translates this suffix into English. When this suffix is added to a sentence it changes the word order of the English sentence and adds a question mark to the end:
Hol 'oH "It is a language."
Hol 'oH'a' "Is it a language?"
Not all questions have the -'a' suffix. When you are using a question word (who, what, where, when, why, how) you do NOT use the -'a' suffix. It is only used to turn a statement into a yes/no question.
In this sentence there is no actual verb, 'oH is a pronoun. However, pronouns can be used as if they were a verb to act like the verb "to be". So when the pronoun 'oH ("it") is used in this way it is usually translated as, "It is," and can take some verb suffixes (like the interrogative suffix -'a').
The noun suffix -'e' has a few different uses that we don't really cover in this course. The most common one is for emphasis. Using the -'e' noun suffix is almost always optional, but there is one circumstance where it is not optional and is required. When using a pronoun as if it was the verb "to be", it includes the subject and the verb within that pronoun. In the sentence, Hol 'oH, the 'oH pronoun represents both "it" and "is". But what if we want a specific subject. In the English sentence, "The Klingon language is a language," (it's a bit redundant, but looking at the grammar is useful), "The Klingon language," is the subject. But to say, "is a language," we have to use the pronoun 'oH and the pronoun is already the subject. We can't have two subjects and so instead we indicate "The Klingon language" as a topic by marking it with the -'e' noun suffix. In this case, we interpret the topic ("The Klingon language") as the same as the subject ("it"). When -'e' is used as a topic marker, the topic usually goes at the front of the sentence, but when used with a pronoun as verb "to be", it follows the pronoun:
Hol 'oH tlhIngan Hol'e' "The Klingon language is a language."
Hol 'oH'a' tlhIngan Hol'e' "Is the Klingon language a language?"
As you can see, the -'e' suffix doesn't have a word that translates it. It is a grammatical structure that is required and it is one of the most common errors for beginner and intermediate speakers, because it has no equivelent word or structure in the English sentence.
Each of these suffixes are explained in separate Tips & Notes, but I know it’s a lot of new information and some details are bound to be difficult to understand or slip through the memory. However, since Duolingo has hidden the Tips & Notes I want to make sure you know about them and where to find them. If you have not been reading the Tips & Notes, I would like to ask that you review those so we don’t have to repeat too much of the information that we have explained there.
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/. You can still do it on your mobile device, but you will have to use the web browser instead of the app (or you can do it from a computer). When you click on a Skill, it will expand to reveal a Start button, a key, 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 question, explaining what you didn’t understand or what seems contradictory to you.