しろはずっと待っていた。
This is what I got.
shiro wa zutto matte ita
white been waiting. I don't know what the いた means.
The context is unknown. But as I think:
しろ ( Shiro ) is usually a name of dog. (Or, cat, or other animal. or other something. Sometimes person's name. nickname.).
This sentence is the past (or, perfect) form of the following sentence:
しろはずっと待っている --> Shiro has been waiting (for long time, or, in patience).
where, "ita" is past/perfect form of "iru".
Shiro wa zutto matta. --> Shiro waited (for long time, etc.), Shiro was waiting (for long time, etc.)
Shiro wa zutto matte-ita --> Shiro had been waiting (for long time, or, in patience, etc.)
This is very simple and easy sentence. But grammatically maybe a bit difficult.
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matsu [to wait], verb
matsu + ta [past/perfect. suffix, particle] --> matta
matsu + te + ita [p/perfect of iru] --> matte-ita
mrd
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Edit:
I wrote the above explanation in very short time (I hadn't time. I had other thing to do.)
So, here, more detailed explanation.
"いる IRU" is the basic verb in Japanese.
It has mainly two meanings or usages.
1) [special verb] to be, to exist
2) verb indicating "progressive form". In this case, "[Verb] + -iru". (Usually particle "て te" is added between [Verb] and -iru. So "[Verb] + te + iru" is usual form.
For instance:
example: usage 1):
猫がいる。 Neko ga iru --> Cat is. or, There is a cat.
少女が野原にいる。 Shoujo ga nohara ni iru. --> A girl is in the field. or, There is a girl in the field.
example: usage 2):
わたしは考えている。 Watashi wa kangaete iru. --> I am thinking. [progressive f.]
kangae + te + iru = kangaeteiru
わたしは待っている。 Watashi wa matte iru --> I am waiting. [progressive f.]
machi + te + iru --> mat-te iru --> matteiru
++ "Machi te iru" is the original form. But it is changed to "Matte iru" in real usage (in contemporary Japanese).
( "machi-" is one of conjugating form of regular verb "matsu". )
"いた ita" is past/perfect form of verb "iru". (Ending form of conjugation.) Therefore:
わたしは待っていた。 Watashi wa matte ita --> I was waiting. [past progressive f.]
In the case of しろはずっと待っている [ Shiro wa zutto matte iru ]
"zutto" is (a kind of) Adverb. Implying
continuously, for long time, in patience, etc. in this case.
しろは待っている Shiro wa matte iru --> Shiro is waiting
しろはずっと待っている Shiro wa zutto matte iru --> Shiro has been waiting
++ zutto implying "present perfect, progressive". Thus:
しろは待っていた Shiro wa matte ita --> Shiro was waiting
しろはずっと待っていた Shiro wa zutto matte ita --> Shiro had been waiting
These explanations are maybe right, I think.
( note: "particle" -- postposition, or postpositional particle, 助詞 joshi )
mrd