It is appropriate to use their when the relative noun or pronoun is in the third person plural:
'They do not look after their dog properly.'
'Mary and Ann do not look after their dog properly.'
'Mary and her sisters do not look after their dog properly.'
His and her relate to masculine and feminine nouns or pronouns in the third person singular:
'He does not like his English teacher.'
'Peter does not like his English teacher.'
'Jane does not like her English teacher.'
It is becoming increasingly common to use their when the noun or pronoun is singular but its gender is indeterminate or unknown:
'I saw someone lurking in the alley but I could not see their face.'
'Everybody is responsible for their own safety.'
This usage is ungrammatical, but avoids two potential problems:
1) Using 'his' to mean 'his or her' or 'his and her'. This used to be universally acceptable, but is no longer considered to be so.
2) Using 'his or her' or 'his and her' in full, wherever such phrases are technically correct. This is laborious and clumsy.
The choice that an individual writer makes is a personal one, and will depend on a number of considerations, including the degree of formality required in the piece of writing.
Here are some alternatives to 'Everybody is responsible for their own safety.' I offer no comment on their grammatical correctness or their acceptability; the choice is yours!
'Everybody is responsible for her own safety.'
'Everybody is responsible for his own safety.'
'Everybody is responsible for his or her own safety.'
'Everybody is responsible for her or his own safety.'
'We are all responsible for our own safety.'
'You are all responsible for your own safety.'
Both are correct in different usages. We say " This is his and her house" but "This house is his and hers."
"His and hers" is correct; the phrase denotes "ownership".
Either can be correct, depending on the rest of the sentence:
She and her daughter.
he and his father
I'm not sure but my father seems to have it.
"On a train" is correct grammar.
It is correct if you are talking about more than one nephew. If only one nephew is involved, it is nephew's father. My nephew's father is my brother. I am talking about one specific nephew. If you mean to refer to the father of your nephews, then it would be nephews' father.
The grammar is correct as it is.
Grammar.
I'm not sure but my father seems to have it.
No, "will be had" is not a correct grammar. The correct grammar would be "will have."
No, it is correct grammar, not a correct grammar.
The correct grammar is: "Are those correct?"
"On a train" is correct grammar.
no_____If the sentence is You do do that (meaning You are in the habit of doing that) the grammar is perfectly correct and the sentence 'does have correct grammar'.
I think you mean "When was your father born?"
No, the correct grammar would be: "July has just started."
It is correct if you are talking about more than one nephew. If only one nephew is involved, it is nephew's father. My nephew's father is my brother. I am talking about one specific nephew. If you mean to refer to the father of your nephews, then it would be nephews' father.
Grammar.
Yes, that is correct grammar.
No, the correct grammar would be "I hate you the way you hate me."