Use of Still, Yet and Already:
https://preply.com/es/blog/2014/11/06/el-uso-de-still-already-y-yet-en-ingles/
These words are often used with the present
perfect tense, although they can be used with other
tenses.
We use ever in interrogative sentences:
- Have you ever been to the
United States?
- Have you ever traveled by train?
- Have you ever failed a class?
We use never in affirmative sentences, but the meaning is negative, it means NUNCA
- I have never cheated in
an exam.
- My son has never been to Moscow.
- My brother have never gone to London.
In sentences with the verb in negative, we use ever instead of never.
- I would't ever say that.
This is the same as saying: I would never say
that.
With other word with a negative meaning, we also
use ever intead of never.These words are: without, hardly, nobody/no one,
nothing.
- Without ever seeing him.
- I hardly ever do that.
- Nobody would ever do that.
- Nothing is ever ready on time.
We use just to express a recently completed action, and it means ‘a short time ago’.
In the present perfect, ‘just’ comes between the auxiliary verb (‘have’) and the past participle.
- The cat has just caught a bird.
- The guests have just arrived.
- I have just finished my homework.
We use already to express that something has happened sooner than expected. ‘Already’ usually comes in mid-position.
- Don't forget to bring your book! Oh, I
have already brought it.
- The boys are going to pack, aren't they? No. They have already packed.
- Is Adam going to buy a new car? No, he isn't. He has already bought it.
Still is used to talk about something that hasn’t finished – especially when we expected it to finish earlier. It usually comes in ‘mid-position’.
- I’ve still got all those letters you sent me.
Still is often used with other tenses as well as the present perfect.
- She is still working.
- The baby is still asleep.
- We are still wainting for his reply.
- It is still raining.
- Are you still working in the bookshop?
We use yet in interrogative and negative sentences. In interrogative sentences, it means the
same as already, and is used to
talk about something which is expected to happen. In negative sentences, it is the same as still, and it suggests a time later than expected.
- Have you finished your homework
yet? No, I haven't done it yet.
- Has your father seen your report? No, he hasn't seen it yet.
- Have the visitors arrived? No, they haven't arrived
yet.
We use For when we measure the duration – when we say how long something lasts: For + a period of time
To measure a period of time up to the present, we use the present perfect tense
and not the present tense.
- I have known her for a long time. (Correct)
- I know her for a long time. (Incorrect)
- I have lived here for ten years. (Correct)
- I live here for ten years. (Incorrect)
The present tense with For refers to a period of time that extends into the future.
- How long are you here for? (Until when)
- How long have you been here for? (Since when)
In reality, we can use all verb tenses with For.
However, we don't use For with expressions such as all day or all the time.
- I was there all day. (Correct)
- I was there for all day. (Incorrect)
Since gives the starting point of actions, events or states. It refers to when
things began: Since + a point in time (in the past), until now.
- I've been waiting since 7 o'clock.
- I have known him since January.
With since we use the present perfect tense or the past perfect tense.
- I have been here since 5 o'clock and I am getting tired.
- I had been working since 5 o'clock and I was getting tired.
Since can also be used in the structure It has been + period of time + since.
- It has been two months since I last saw her.
- It has been three years since the last earthquake.
ACTIVITIES:
http://www.better-english.com/grammar/stillyet.htm
http://autoenglish.org/gr.presper.i.htm
http://perso.wanadoo.es/autoenglish/gr.presper.i.htm
http://www.englishexercises.org/makeagame/viewgame.asp?id=3211
http://www.carmenlu.com/second/grammar/presentperfect2_2.htm
http://baladre.info/english/sedaviwebfront/preperfwords.htm
http://baladre.info/english/sedaviwebfront/yetstill2.htm
http://www.learn-english-today.com/lessons/lesson_contents/exercises/already-still-quiz1.htm
http://www.tolearnenglish.com/exercises/exercise-english-2/exercise-english-49804.php