1. I need someone to find some photos to post on the blog.

2. I need someone who will find some photos to post on the blog.

3. I need someone who will find some photos so as to post on the blog.

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Are they all the same? Does #1 mean #2 or #3?

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4. I need someone to go there.
5. I want someone to go there.

(Is 'to go' an objective complement in each sentence?)

1. I need someone to find some photos to post on the blog.

(Or does 'to post -' modify 'some photos'?)

1. I need someone to find some photos to post on the blog.

1-2. I need someone who will find some photos which he will post on the blog.

1-3. I need someone to find some photos so that he may post on the blog.
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Does #1 mean #2?

1. I need someone to find some photos to post on the blog.

1-2. I need someone who will find some photos which he will post on the blog.

1-3. I need someone to find some photos so that he may post on the blog.
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Does #1 mean #2 or #3?

Sentence 1 means the same as both the other sentences in your last post.

In the first post, you used "so as" in sentence 1-3. That's not correct phrasing. If you omit "so as" the sentence will be fine.

1. "I need someone to find some photos to post on the blog." In this sentence, the phrase "to find some photos" serves as an infinitive phrase that explains the purpose or intention of the action "I need someone." It indicates that the person is needed in order to perform the action of finding photos. The photos are intended to be posted on the blog.

2. "I need someone who will find some photos to post on the blog." This sentence conveys the same meaning as the first sentence but provides additional emphasis on the aspect of finding photos. By using the phrase "who will find," it implies that the person being sought is expected to actively engage in the process of finding the photos.

3. "I need someone who will find some photos so as to post on the blog." This sentence is similar to the second one but includes the phrase "so as to" before "post on the blog." The phrase "so as to" serves as a conjunction that introduces a purpose or result. It clarifies that the photos are being sought for the specific purpose of posting them on the blog.

Overall, all three sentences convey the same essential meaning of needing someone to find photos for the purpose of posting them on the blog. The nuances in wording may vary based on emphasis or style, but the core message remains consistent.

Regarding the second set of sentences:

4. "I need someone to go there." In this sentence, the phrase "to go there" acts as an infinitive phrase that describes the purpose or objective of needing someone. The person is required in order to carry out the action of going to a particular location.

5. "I want someone to go there." Similarly, in this sentence, the phrase "to go there" serves as an infinitive phrase explaining the intention or objective of needing someone. The person is wanted for the purpose of going to a particular location.

In both cases, "to go" is used as an infinitive phrase rather than as an objective complement. It functions to indicate the goal or action that the person is needed or wanted for.