“This is the largest tree of any I have seen.” The meaning clearly is, that of all the trees I have seen this is the largest. Hence, of any should be changed to of all.
Elder and eldest are terms applied chiefly to persons, generally in speaking of members of the same family, while older and oldest are applied to persons of different families, and also to things.
“His elder brother died yesterday.” “His eldest sister has gone to Italy on her wedding trip.” “Our oldest neighbor was born in 1825.” “This oak is older than that pine.” The foregoing sentences illustrate the best usage as applied to the comparatives older and elder and the superlatives oldest and eldest.
When the direct comparison is made the word older is used, followed by the conjunction than; as, “My father is older than my mother.” But when the comparison is assumed the word elder should be employed; as, “My father is the elder of my parents.”
Only
Perhaps no other word in the language is so often misplaced as the word only. The only general rule is to place it as near as possible to the word which it modifies. “He only lent me a dollar” means that he did not make me a present of the dollar, but expects me to return it. “He lent me only a dollar” means that the sum lent was neither greater nor less than one dollar. The former expression is often used when the latter should be.
“Only the man walked to the post-office to-day.” The woman did not walk with him.
“The man only walked to the post-office to-day.” He did not ride or drive.
“The man walked only to the post-office to-day.” He did not go so far as the store.