The train ___ arrive at 11 am but it was an hour late.
Infinitive Clause/Phrase: To + verb-এর base form, to+verb-এর base form + object এবং to + verb-এর base form + adverbial কে infinitive clause বলে। এদেরকে infinitive phrase ও বলা হয়।
যেমন-
He wants to go.
This is the way to see city.
We need to act quickly.
I am glad to know your success.