I + verb and I + do + verb

[Jadoon 84]

Would someone please teach me what is the difference between the following sentences?

1, I play football. (Present Indefinite tense)

But

2, I do play football. (why "DO" is used here, does it change the meaning of the sentence? when should I use "I + Do + verb? )

with kind regards

[abaka]

The "do" is emphatic, put in to remove any doubt that you might not play football. For example:

Q: I know you're a good swimmer, but I've never seen you play any team sports.
A: Well, I do play football.

[miwalko]

Is it okay to use this emphatic "do" in academic writing as well?

[abaka]

Yes, occasionally. Emphasis is a rhetorical device, but the tone of academic writing should be as neutral as possible. The emphatic form is similar in intent and meaning to italics: said too often, it only annoys.

[TheParser]

***** NOT A TEACHER *****


Hello, Mr. Jadoon:

May I add two more examples to abaka's excellent answer?

*****

Tom: My father speaks 10 languages.

Mona: No way, dude! That's impossible.

Tom: He does speak 10 languages! If you don't believe me, come over tonight and listen to him.

*****

Monica: The president of our country called me last night on the phone.

Joe: Stop kidding, will you!

Monica: I'm not joking. He really did call me last night. The call was recorded. I'll let you listen to it.

*****

P.S. If you wish to emphasize the verb "to be," do NOT use "do." Just say the word loudly:

Tom: My girlfriend is the most beautiful girl in this town.

Robert: I don't think so.

Tom: She IS the most beautiful girl in this town. Everyone says so.