Я внимательно прочитала контракт дома и поняла, какие условия мне подходят.

Because both verbs are in the past tense feminine singular.

In Russian past tense, verbs agree with the gender and number of the subject:

• я прочитал, понял = if the speaker is male
• я прочитала, поняла = if the speaker is female

So this sentence tells you that the speaker is female.

The sentence describes two completed actions in sequence:

1. прочитала контракт = read through the contract
2. поняла = understood / realized

Both verbs are in the past because both events happened in the past. The use of и links them as a natural sequence: she first read the contract, and then she understood which terms suited her.

This is about aspect.

• читать = imperfective, focuses on the process of reading
• прочитать = perfective, focuses on finishing reading

So:

• Я читала контракт = I was reading / I read the contract (process, no emphasis on completion)
• Я прочитала контракт = I read through the contract / finished reading it

Here, the speaker means she completed reading it, so прочитала is the natural choice.

Again, this is aspect.

• понимать = imperfective, to understand / be understanding
• понять = perfective, to come to understand, to realize

In this sentence, the meaning is not just that she generally understood something, but that she reached an understanding after reading. That is why Russian uses поняла.

So поняла here is close to realized or came to understand.

Внимательно means carefully, attentively, or with attention.

It modifies прочитала:

• Я внимательно прочитала контракт = I read the contract carefully

It tells us how she read it. In Russian, adverbs like this often come before the verb, though other word orders are possible.

Дома means at home.

It is a very common adverb in Russian:

• Я дома = I am at home
• Она читала дома = She was reading at home

By contrast, в доме literally means in the house/building. That usually focuses more on the physical location inside a building, not the idea of home as a place where someone lives.

So here:

• дома = at home, naturally
• в доме would sound different and less idiomatic in this context

Because какие условия мне подходят is a subordinate clause.

The structure is:

• Я ... поняла, какие условия мне подходят.
• I understood / realized which conditions suit me.

In Russian, subordinate clauses are normally separated by a comma. The word какие introduces the clause.

Because какие is the normal word for which / what kind of in this kind of indirect question.

• какие условия мне подходят = which conditions suit me

Которые can also mean which, but it is usually used when choosing from a more specific, already defined set, or in relative-clause structures. In this sentence, какие is the natural choice.

So a learner should think of this as:

• Я поняла, какие условия мне подходят = I understood which terms are right for me

Because условия is the subject of подходят.

In the clause:

• какие условия мне подходят

the thing doing the suiting is условия = conditions / terms.

So grammatically, it is:

• условия подходят = the conditions suit

That is why условия is nominative plural.

Because the verb подходить in this meaning works like to suit or to be suitable for someone.

The pattern is:

• что подходит кому
• something suits someone

So:

• Эти условия мне подходят = These conditions suit me
• Мне это не подходит = This doesn’t suit me

The person is put in the dative case:

• мне = to me / for me

That is why you get мне подходят, not я or меня.

Because the speaker realized something that is still true as a general fact: which terms suit her.

Compare:

• поняла, какие условия мне подходят = understood which terms suit me
• literally, the clause states a present/general suitability

Russian often uses the present tense in subordinate clauses like this when the meaning is timeless, general, or still valid now.

If you changed it to a past form, the meaning would shift and sound less natural in this context.

Because условия is plural.

Russian verbs agree with their subject in number:

• условие подходит = the condition suits
• условия подходят = the conditions suit

Since условия is plural, the verb must also be plural: подходят.

Both контракт and договор can mean contract/agreement, but there can be a nuance.

• договор is often the broader and very common legal/business word for an agreement
• контракт is also common, and often sounds a bit more like a formal contract, sometimes in business or employment contexts

In many contexts they overlap, and either may be possible. In this sentence, контракт is perfectly natural.

No, Russian word order is fairly flexible, but this version is very natural.

• Я внимательно прочитала контракт дома и поняла, какие условия мне подходят.

This order sounds neutral and clear:

• внимательно gives the manner
• контракт is the object
• дома gives the location
• then the second action follows

You could move some parts for emphasis, for example:

• Дома я внимательно прочитала контракт...
• Я дома внимательно прочитала контракт...

These are also possible, but they shift emphasis slightly. The original sentence is a good neutral model.