Yes, preposition „w” can connect with locative or accusative, but accusative is used for 1)specifying time („mam to zrobić w piątek ”= 'I have to do it on Friday') 2)specifying direction („Strzelił w drzwi” = 'He shot at the door') and locative is used for specifying that the verb is happening 'inside of something' („mieszkał w Krakowie” = 'He lived in Cracow') – there are other uses for both cases, but those are unimportant here, so I left them out.
Now, consider immery's comment above:
'Leżeć w łóżku - under covers, bed prepared for sleeping Leżeć na łóżku- on top of covers when bed is prepared for a day, eg when trying bed in shop'
The logic of the Polish language here is, that since you are in between the duvet, cover, whatever and the top surface of the actual bed, you are 'inside' of the bed, so it requires locative here. ;)
Hope that helps. :)
In present tense, it's very easy to mix up the verbs 'lay' and 'lie', but one way to keep them apart is to remember that 'to lay' requires a direct object (eg. I am laying a book on the table), while 'to lie' does not take a direct object (eg. The cat is lying on the sofa). In this case, there's no direct object, so we use "lie".
Beware that the past tense of "to lie" is "lay", so "I lay in bed" would be a correct sentence but only in past tense, which the Polish sentence is not.
No, they are not similar in a slightest way. OK, 3 letters are the same, but that's just by accident, they're not related at all.
a) kłamać (imperfective), skłamać (perfective)
b) kłaść się (imperfective), położyć się (perfective)
c) leżeć (imperfective only) = to be in a horizontal position
If you're level 7, I guess you don't have to worry about perfective verbs yet ;)