He worked late to meet the project deadline.
Here, the infinitive 'to meet' is used as -

• The required answer is - Adverb.

• Infinitive as Adverb:
- He worked late to meet the project deadline. Here "to meet" is used as - an adverb.
- Here "to meet" describes why he worked late.
- অর্থাৎ, এটি worked verb কে modify করছে।

• Infinitive as Adjective:
- It has no possibility to appear. Here the infinitive 'to appear' is used as - an adjective.
- কারণ এখানে বাক্যস্থিত noun word 'possibility' কে 'to appear' modify করছে।

• Infinitive as Noun:
- It is dangerous to drive on this slippery road. Here the infinitive 'to drive' is used as - a noun.
- এখানে introductory 'it' এর subject হিসাবে 'to drive' হচ্ছে noun.

• Infinitive হচ্ছে verb এর base form অথবা to + base form.

• Infinitive দুই রকম হতে পারে-
1. To-যুক্ত infinitive. যেমন: To err is human. এবং;
2. To-বিহীন infinitive. যেমন: Let me go.
- To-বিহীন infinitive form-কে bare infinitive বলা হয়।