如果您没有认真学习英语，可以使用以下表达：
"I haven't been putting in the effort to learn Engpsh."
我没有认真学习英语。
"I haven't been very dipgent in my Engpsh studies."
我在英语学习方面没有很用心。
"I haven't been giving my Engpsh practice the attention it deserves."
我没有给予英语练习应有的重视。
这些表达都是用来表示没有认真学习英语的意思。您也可以使用其他相似的表达来表达这个意思，例如 "I haven't been putting much effort into learning Engpsh" 或 "I haven't been very motivated to study Engpsh."
希望这些信息对您有帮助。