こんにちは (Konnichiwa) Abgueguen and toru e,
Thank you for your question!
Just as toru e says, "seems like" uses the grammar construction そう です (sō desu).
When you use そう です (sō desu) with the stem of a verb, you can express that something "seems like" or "looks like" it is about to happen.
To find the stem of a verb, just remove the ます (masu). From there, simply add そう です (sō desu).
If you need a little practice on verb stems, you can check out this brand new lesson, which explains everything in far more detail!
The stem of ねむれます (nemuremasu) is ねむれ (nemure), so to say "seems like (I) can sleep," we say ねむれそう です (nemuresō desu).
When you use the plain form ねむれる (nemureru) with そう です (sō desu), the meaning changes completely!
When you use a verb in the plain form with そう です (sō desu), you can express "hearsay," or something you have heard from someone.
So, if you said ねむれる そう です (nemureru sō desu), it would mean "apparently (you) can sleep."
It's easy to confuse these two, so be careful with this one!
I hope this helped. Please let me know if you have any more questions.
べんきょう を がんばって ください！ (Benkyō o ganbatte kudasai!)