Nusrat likes to play ludo. Here “to play” works as

Tense, person, কিংবা number অনুসারে যে  verb পরিবর্তিত হয় না তাকে Non - finite verb বলে। 
অর্থাৎ, A Non-finite verb is a form of verb that is not limited by person, number or tense in a sentence and cannot act as main verb.

• আলোচ্য বাক্যে to play, Non - finite verb এর উদাহরণ।

এখানে main verb বা finite verb হলো “likes.”

Source: English & Bengali Online Dictionary & Grammar