Can we Start a Sentence with "And" or "But"?

Is it acceptable to begin a sentence with the word and or but ?

The answer is yes. It is perfectly acceptable to start sentences with the conjunctions and and but. However, it is slightly informal. If formality is your goal, choose more formal language.

Informal:

    But we hope to write an agreement today.

    (no comma needed after but)

Formal:

    However, we look forward to writing an agreement today.

    Nevertheless, we look forward to completing the agreement today.

Informal:

    And Clare knows how to write a good report.

    (no comma needed after and)

Formal:

    In addition, Clare is skilled in writing reports.

    Furthermore, Clare is a skillful report writer.

There's one rule you do have to follow: Meet your reader's needs. 

For example, if your supervisor (or your supervisor's supervisor) doesn't approve of beginning a sentence with a conjunction, avoid it. After all, he or she is one of your most influential readers.