is a verb particle for past or present tense.  It precedes the question ending.

verb လား
  verb particle question ending
Does (someone) verb?/ Is (something) adjective?

သူ လာသလား။   Does he come?

ကျွန်တော် မှားသလား။   Am I wrong?

တယ်   is a positive sentence ending for past or past or present tense.

ပါ   as a verb particle is used for politeness.

verb ပါ တယ်
  verb particle sentence ending
(Someone) verbs./ (Someone) is adjective.

သူ လာပါတယ်။   He comes.

ခင်ဗျား မှားပါတယ်။   You are wrong.


and ဘူး    sandwich verbs in negative statements.

verb ပါ ဘူး
negative prefix   verb particle negative sentence ending
(Someone) does not verb./ (Someone) is not adjective.

သူ မလာပါဘူး။   He does not come.

ခင်ဗျား မမှားပါဘူး။   You are not wrong.


လား   is added to negative statements to construct negative questions.

verb ဘူး လား
negative prefix   negative sentence ending question ending
Does not someone verb?/  Is not someone adjective?

သူ မလာဘူးလား။   Does not he come?

ခင်ဗျား မမှားဘူးလာ။   Are not you wrong?

Note:  Use of the verb particle ပါ in negative questions is rare.