Do We Have To Stick W/ One Tense For Each Sentence?

PreciousJones
So

He told me he is coming and he is going to bring his parents with him too. This is incorrect?

This kind of tense combination is not uncommon in conversational English and is quite acceptable. (In conversation, "he is" would normally be contracted to "he's".) You can, of course, only use this style if the thing you're describing is in the present or future.

Why does the websites say otherwise?

A sentence that begins with past tense such as told or said has to be all one tense(past tense)?

Where exactly does anyone say that such a sentence must be "all one tense"?

"He told me he'd (= he had) been ill."

"He told me he's (= he is) a Buddhist."

"He told me he's (= he has) found a job in London."

These are all OK.

Regarding your original sentence, "He told me he was coming" may be viewed as more formally correct than "He told me he's (= he is) coming". Nevertheless, the latter sentence is used by native speakers in real life, and I, for one, have no objection to it.

From the websites:

If the reporting verb (i.e. said) is in the past, the reported clause will be in a past form. This form is usually one step back into the past from the original.
For example:

• He said the test was difficult.
• She said she watched TV every day.
• Jack said he came to school every day.

If simple present, present perfect or the future is used in the reporting verb (i.e. says) the tense is retained.
For example:

• He says the test is difficult.
• She has said that she watches TV every day.
• Jack will say that he comes to school every day.

PreciousJonesIf the reporting verb (i.e. said) is in the past, the reported clause will be in a past form.

"a past form" is rather different from "all one tense"!

So he said the test is difficult. Is this also a past form?

PreciousJonesSo he said the test is difficult. Is this also a past form?

No, I was referring to the fact that "a past form" does not exclude sentences such as:

"He told me he had been ill."

"He told me he was coming."

Your "all one tense" could be understood as excluding these.

Mr WordyNo, I was referring to the fact that "a past form" does not exclude sentences such as:

"He told me he had been ill."

"He told me he was coming."

Your "all one tense" could be understood as excluding these.

... the point being that these are formally correct, so it would be very surprising if any website said they were not proper. The other "present-versus-past" issue is more a matter of how strict one is in failing to acknowledge the legitimacy of forms such as "He told me he's coming".