いったん~ば/と/たら   => Once you do something N2
Necessity, obligation
ようだったら => If... N2
Condition (hypothetical condition)
…たら…だろう => If only... N3
Condition (condition contrary to reality)
~たらんとする      => want to become, worthy of ~ N1
たぶん => Maybe... N4
Speculation
~んがため(に)/~んがための      => in order to ~ N1
たぶん => perhaps; probably N4
たとたん(に) => as soon as; just as ~ N3
~たらどんなに … か => It will be great if something is done N1
Condition (condition contrary to reality)
~たらどんなに…か => It will be great if something is done N1
Condition (condition contrary to reality)
… たら => Introduction N4
How to say the beginning
たらどうですか => why don't you; how about ~ N4
Invite and advise