"Send me a letter." Here, send is a/an:

Here, send is a transitive verb.

Transitive verbs এর সাধারণ Structure হচ্ছে : subject + verb + object

- Transitive verbs involve not only the subject, but also someone or something else, the object. অর্থাৎ Transitive verb এর কেবল subject নয় বরং এক বা একাধিক Object ‍ও থাকবে।

যেমন: She has many friends, but (she) admires Victoria most.

নিচের transitive verb গুলোর দুটো Object আছে। একটি প্রত্যক্ষ অপরটি পরোক্ষ:
- She brought me my breakfast in bed on a silver tray.

অপরদিকে,

Intransitive verb এর সাধারণ Structure হচ্ছে: subject + verb
- If an action concerns only one person or thing, you mention only the person or thing that carries out the action (the subject) and the action itself (the verb).
- Verbs which describe such actions are called intransitive verbs, e.g. I waited and waited, but nobody came.

Source: Cliffs TOEFL