Hi! i am confused on two things that involve reflexive verbs and accent marks :) the question: Write complete Spanish sentences expressing the affirmative or negative command, depending on if no is present.
11. no dormir ("o" to "ue" stem change) tarde (late):
my answer for this example: No te duermas.
my teacher told me that this is not a reflexive verb. and that I need to add tarde after the verb. where and how?
13. ponerse la ropa:
my answer for this question: Ponte la ropa.
my teacher told me to add the accent mark on the verb that must be added when adding a reflexive pronoun to the command. where and how ?
thanks so much!

Hey there! I'm happy to help!

11.

Dormir actually isn't a reflexive verb. Dormir is a word that can only be used in regards to oneself, so it is not reflexive as that clarification isn't needed. What do I mean?

Take the word "acostar". This means to put into bed. You could say la mamá acuesta a su hijo (the mom puts her child to bed). However, you could make it reflexive to say Me acuesto (I go to bed).

We have a reflexive form to differentiate between those two things. Dormir doesn't need it because you can't "sleep" someone else so it will never been used in that context.

And with tarde, you just put it at the end of the sentence.

No duermas tarde.

13. It appears that you are correct. Ponte la ropa is written correctly and sounds correct. No accent is needed in the sentence. It seems like your teacher wants you to write pónte, but that would be redundant and incorrect because in Spanish the penultimate symbol is naturally accented, so an accent is only needed if it breaks that rule or for writing purposes (si vs sí.

Have a wonderful day and keep on learning! :D

the first is correct, the second is "la tienda de descuentos" meaning "the discount store", and the third is "ayer" meaning "yesterday".