Determine the sentence type: ''If it rains, the match will be postponed.''

• ''If it rains, the match will be postponed.'' - Complex sentence. 
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• Complex sentence: 
- যে sentence এ একটি Principal clause এবং এক বা একাধিক Subordinate clause থাকে, তাকে Complex sentence বলে। 
- Complex sentence এর subordinate clause এর শুরুতে সাধারণত if, though, although, as, because, since, so that, that, until, till, unless, when, why, who, which, where, how, before, after, whether, while বসে।
সুতরাং, নিয়মানুযায়ী - ''If it rains, the match will be postponed.'' - এই বাক্যটি হচ্ছে - Complex sentence. 

Source: Website English Wizard, Advanced Learners Communicative English Grammar and Composition, Oxford Practice grammar and A passage to the English Language by S.M. Zakir Hussain.