Present Tense in Serbian - questions and negative forms

Prezent u potvrdnom, upitnom i odričnom obliku

a. one example is with a transitive/intransitive verb, while the
b. example is with the 'se' verb (see the explanation in this post)

affirmative
(I sing every day) > Ja pevam svaki dan
(I comb (myself) ) > Ja se češljam

interrogative
(do you sing every day?) > Da li pevaš svaki dan?
(What do you sing every day?) > Šta pevaš svaki dan?
(Do you comb (myself) ) > Da li se (ja) češljam ?
(Who combs (themselves)? ) > Ko se češlja?


negative
(I don't sing every day) >Ja ne pevam svaki dan OR Ne pevam svaki dan.
(I don't comb (myself)) > Ja se ne češljam. = Ne češljam se.

******** EXERCISE******** mark the sentences as C *correct or I*incorrect :

1. Ja se igram.
2. Mi pevam.
3. Da li se ja umivamo?
4. Ne doručkujemo u 8.
5. Ti pereš.
6. Ja idem u Beograd.
7. Zovem Mario.
8. Kupam se svaki dan.
9. Gde ste se upoznali?
10. Imam čas svaki dan.