" There is " & " There are "

There is = There are = است /ast/

a book = كتابي /keta:bi/ (We could say يك كتاب /yek keta:b/ for 'a book', but here use NOUN+/i/sound is better. Examples:a tree درختي /kerakhti/; a table ميزي /mi:zi/.
on = روي /ru:ye/
the table = ميز /mi:z/

There is a book on the table = كتابي روي ميز است
There are two books on the table = دو متاب روي ميز است
There are ten books on the table = ده كتاب روي ميز است
There are 25 books on the table = تيست و پنخ كتاب روي ميز است

Notes: If the subject is human in this structure, it has two way for "there are".
There are = است /ast/ or هستند /hastand/
Examples:
There is one boy in the class = پسري در كلاس است /pesari dar kela:s ast/
There are two boys in the class = دو پسر در كلاس است/do pesar dar kela:s ast/
Or دو پسر در كلاس هستند /do pesar dar kela:s hastand/

see 92-93

'when' & 'while' in Past Continuous Tense

1. Translate the Past Continouns Tense first
2. Use /keh/ for ' WHEN'
3. Translate the Simple Past Tense

Example 1:
I was eating lunch when he called.

To call = /telefon kardan/ or /zang zadan/

/da:shtam na:ha:r mi khordam keh u: telefon kard/

Example 2:

I was watching TV when the electricity went.

/da:shtam televiziyu:n/ nega:h mi kardam keh bargh raft/

Example 3:

She was going when I saw her.

/da:sht mi raft keh u: ra: didam/

Notes: The same rule is applicable for ' while'

Past Continouns Tense

Remember in this Tense, I was (in English) = I had (in Persian)

Let's translate " I was writing"
1. First, change verb "have"
to have = داشتن /da:shtan/
Delete ن /nu:n/, = داشت /da:sht/

Now, try to use داشت with all subjective pronouns in Simple Past Tense:
I had = من داشتم /man da:shtam/
You had = تو داشتي /to da:shti/
He had = او داست /u: da:sht/
We had = ما داستيم /ma:da:shtim/
You had = شما داشتيد /shoma: da:shtid/
They had = انها داشتند /a:nha: da:shtand/


2. then, change the main verb " write"
to write = نوشتن /neveshtan/
Delete ن /nu:n/, = نوشت /nevesht/

I wrote = من نوشتم /man neveshtam/
You wrote = تو نوشتي /to neveshti/
He wrote = او نوشت /u: nevesht/
We wrote = ما نوشتيم /ma: neveshtim/
You wrote = شما نوشتيد /shoma: neveshtid/
They wrote = انها نوشتند /a:nha: neveshtand/

put مي /mi/ before the main verb, so,
I was writing = من داشتم مي نوشتم
You were writing = تو داشتي مي نوشتي
He was writing = او داشت مي نوشت
We were writing = ما داشتيم مي نوشتيم
You were writing = شما داشتيد مي نوشتيد
They were writing =انها داشتند مي نوشتند