Past or Present Perfect?

[RonBee]

Present perfect:
.

He has written three books.
He has died.
He has had an accident.
He has been sick.

[ishana]

Present perfect is perfect answer. Because process of the action is on going i.e for the last month.

[mahmoudnasr]

it's simple past because there is a time expression here. we don't use time expression with present perfect.

[chellamuthu]

Use present perfect because it is on going process.
chellamuthu

[Atchan]

Present perfect is a suitable answer. But I chose past

[sglowski]

If ıt was "for a month" yes yours is the correct one but it is "for the last one month"...

The quote sounds like a non-native speaker of English. Note, for the last week, for the last hour, for the last month, for the last 10 years all include the moment of speaking and therefore require present perfect.

[jack4321]

Nothing is perfect......

[the creative]

I .... haven't seen them for the last month
for: a key word of present perfect tense

[iFranKlin]

I have not seem them.
yes because it's a period of time.
but saying: I did not see them last month.
because there is a specific time, which is last month.
Am I right !!

[jack4321]

It was mine.......

Now i don't have....