Hello Divakaran,

I've found this, which can be a good answer. It's from BBC International Service - Learning English, bbc.co.uk. I don't have anything to add.

Best wishes

Fernando M Díez Gallego

Teacher of English. Teacher-trainer. http://fernandoexperiences.blogspot.com

Granada (Spain)

Lim Chiu Lan from Malaysia asks about prepositional phrases:

Would you be good enough to explain to me what is the difference between these prepositional phrases: good at and good in?

Which of the following is correct: 1) 'I'm good at English' or 2) 'I'm good in English' and 1) 'I'm good at football' or 2) 'I'm good in football'?

Roger replies:

To be good at and to be good in are often interchangeable, Lim, and there is no easy rule to follow. In simple statements, like the ones you have quoted, the standard form appears to be good at as in 'I'm not very good at football'.

However, in this following sentence, to be good in seems more likely than to be good at, i.e:

'He was the best in the class in French, but in mathematics and chemistry he was not so good.'

This is perhaps because with other expressions or verbs denoting assessment or ranking, the preposition in would be required, thus:

'In pharmacology she obtained/scored/gained/attained the highest marks.'

Dear sir,

              Thank you very much.It is a good explanation .Once again thanks for your instant response.

Dear sir,

               Thank you very much for taking pain to attend to my question and hence clearing my doubts.

Hello divakar3368,

I don't know who you are addressing and asking for help. Anyway, It's a pleasure for me to reply to your question. I'm trying to give you some clear clues. May the other teachers give you some practical clues as well.

I'd like to simplify my contribution, for the usage of past continuous is easy.

Let's see. First, past continuous refers to an action in the past, which takes some span of time. Look at this example: 'Yesterday evening, while I was reading, my mobile rang: it was Liona.'

So, during the process of reading or, if you like, during the time I was reading, Liona called me. It's as though a punctual action interrupted or happened in the middle of the action of my reading.

Thus, the past simple and past continuos are in no way alternative.

I wouldn't say any more. If I can help you with more grammar stuff, let me know.

All the best

Fernando M Díez Gallego

Teacher trainer. http://fernandoexperiences.blogspot.com

Hello Divakar3368,

You explicitly asked: " Is the sentence correct, I was reading a novel yesterday.Can we say ,I read a novel yesterday, as an alternative ."

I tell you that both sentences are grammatically 100 per cent correct in their contexts.

Look at your examples again:

 1) "I was reading a novel yesterday."

    a)  --> the Context: Suppose I asked you: " I saw you in the park, yesterday.

         What where you doing there?" Your answer was: "I was reading a novel."

     b) Another context: " I knocked at the door but you didn't open. Weren't you there?"

Your answer(s): "I was watching TV, I didn't here you / I was having a bath /  I was talking on the phone..."

So, please note that we use the Past Progressive When-among other cases- the action bears in itself continuity / progressiveness. Some verbs (of course with past references) postulate the use of the Past progressive such as to watch, play, read, sing, dance, listen..., for they take time when being performed. Other verbs-of perception & to be...- are NORMALLY not used in the progressive (Present nor Past). However, they can be. Look at these examples:

   c) "I love you"  but NOT " I am loving you".

   d) "She has got blue eyes" but not "She is having got blue eyes"

   e) " He thinks that life is getting harder and harder"  but NOT " He is thinking that life is..."

 However, we can say: " He is thinking of divorce"  --> Context: a husband is suffering from his wife's abuses...

or "He is thinking of new investments in Africa"   --> Context: a businessman looking for new markets...

  2) " I read a novel yesterday" 

      --> context: I asked you: "What did you do yesterday?"

      You answered:" I read a novel / I played football / visited my parents...

     --> Context: (Reporting news).

So, here you cannot use the Past Progressive.

However, you can answer: "I was reading a novel / was watching TV / was having a bath / was sleeping... when you knocked at the door / rang me up / at that time...

To sum up, The context determines the use of the tense / form. Think of the verb(s) / action(s) and their contexts then things will be so easier.