I am trying to construct a sentence and I would like to know if this correct form of writing.
他们俩的性格差不多,挺像双胞胎一样.
Is this sentence alright? Can we use 挺 in this manner?
'挺像 X' means 'quite like X'
'像 X 一样' means 'as same as X'
Either "他们俩的性格差不多, 挺像双胞胎的." or "他们俩的性格差不多, 就像双胞胎一样". would make better sentence
就 implies 'exactly'. It is a more suitable adverb for 一样 (the same) than 挺 (quite)
Note:
"他们俩的性格差不多" is grammatically correct , but logically, personality has nothing to do with being twin or not.
I don't think you need 一样:
他们俩的性格差不多,挺像双胞胎。