Here, "have" is not acting as an auxiliary verb. There is no other verb, so it is the principal verb, meaning "possess" or "own". When there is no auxiliary verb, "even", "only",and "just" go in front of the principal verb (or the subject, if they are modifying the subject). In the following examples, the first sentence will have an auxiliary verb, and the second sentence won't. Sally *doesn't only like* math, she likes history too. Bob *only does* his own work. He doesn't do anyone else's. Bob *is just walking* to the store--he isn't doing anything special. I don't know why that's right: it *just is*. And again, all these words can modify the subject or object as well as the verb. 1: "Only Bob came to my party" (modifying the subject)= There was exactly one person at my party. That person was Bob. 2A: "Bob only came to my party": (modifying the verb)=Other people came to my party and gave me presents and gave me money. Bob came to my party, but he didn't do anything else. He sucks. 2B: "Bob only came to my party": (modifying the object)=Bob could have gone to five other parties, but he didn't. He came to my party, and did not go to any other parties. As you can see, 2A and 2B look exactly the same, but have different meanings. When even, only, or just is in front of the verb, you need to use context to decide if they are modifying the verb or the object.

I can write a letter I can only write a letter I can also write a letter I can already write a letter..... nah doesn't work here I can sometimes write a letter I can always write a letter I can hopefully write a letter I can quickly write a letter Only you can write a letter Grammer books, hey! :-)