(3) "He replied that he wished …, and that he intended."
(2), though theoretically free from ambiguity, is practically ambiguous, owing to a loose habit of repeating the subject unnecessarily. It would be better to insert a conjunctional word or a full stop between the two statements. Thus:
(4) "He replied that he wished to help them, and indeed he intended," &c., or "He replied, &c. He intended, &c."
Where there is any danger of ambiguity, use (3) or (4) in preference to (1) or (2).
*29. When there are several infinitives, those that are dependent on the same word must be kept distinct from those that are not.*
"He said that he wished to take his friend with him to visit the capital and to study medicine." Here it is doubtful whether the meaning is—
"He said that he wished to take his friend with him,
(1) and also to visit the capital and study medicine," or
(2) "that his friend might visit the capital and might also study medicine," or
(3) "on a visit to the capital, and that he also wished to study medicine."