ব্যাকরণ (grammar):

Verbs

Bengali verbs are conjugated for person and tense only; they are not inflected for number. For this relay, you only need to know the first- and third-person conjugations in the present and perfect tenses.

Infinitives end with -আ. Verbs are conjugated using fusional suffixes added to the stem, which is formed by removing -a from the infinitive.

In the perfect tense, the main vowel in the stem will shift using one of the following patterns:

আ > এ (example: গাওয়া “to sing” > গেয়েছি “I sang”)
এ > ই (example: লেখা “to read” > লিখেছি “I read”)
ও > উ (example: শোয়া “to lie down” > শুয়েছি “I lay down”)

The Bengali conditional is an invariable form of the verb. You use the perfect stem of the verb (i.e. the one with the shifted vowel as described above) and add the suffix -le.

খাওয়া "to eat" > খেলে "if one eats"
দেওয়া "to give" > দিলে "if one gives"

Nouns

Nouns in Bengali are declined in four cases: direct, objective, genitive, and locative.

The direct case is used for the subject and direct object of a transitive verb and the subject of an intransitive verb. This is the dictionary form of a noun.

The objective case is used for indirect objects, and primarily only for nouns that refer to people. The suffix is -কে.

The genitive case is used for possessive constructions and with many postpositions. The suffix is -(এ)র. Examples:

ছেলে (boy) + বই (book) = ছেলের বই (boy's book)
মাথা (head) + ভিতরে (inside) = মাথার ভিতরে (inside the head)

The locative case is used to signal location in or motion towards a time or place. It can only be used with inanimate nouns. The suffix is -(ত)এ. Examples:

ঘর (room) > ঘরে (in the room)
দিন (day) > দিনে (in/during the day)

Nouns can also be declined for definiteness. The definite suffix changes depending on whether the noun is human or non-human. See table below.

Pronouns

Pronouns are somewhat irregular. The first person pronoun is declined in the table below.

Postpositions

Postpositions come after the noun and often demand either the genitive or direct case.

বই (book) + ভিতরে (inside) = বইয়ের ভিতরে (inside the book)

Numbers

Most of the time, numbers cannot stand alone; they must be suffixed by the measure word -টা. Numbers that come before durations of time do not take a measure word.

এক (one) + বই (book) = একটা বই (one book)
ষাট (sixty) + সেকেন্ড (second) = ষাট সেকেন্ড (sixty seconds)